remove ESP-IDF guard around ethernet interface

__init__.py
	new interface config is already guarded by

		config[CONF_TYPE] in SPI_ETHERNET_TYPES

	in (only) such cases,

	_validate
		will provide a default if one not in config
	_final_validate
		will use this to check for collision with spi component
	to_code
		will generate #define USE_ETHERNET_SPI

ethernet_component.cpp

	#ifdef USE_ETHERNET_SPI
	is the guard we want.
	we don't need (and don't want)
	#ifdef ESP-IDF

ethernet_component.h

	no need for
	using SPIInterface = spi_host_device_t;
	just use spi_host_device_t

	remove ESP_IDF guards
	they are all nested under USE_ETHERNET_SPI guards

esphome/components/ethernet/__init__.py

@@ -175,7 +175,7 @@ def _validate(config):
                     f"({CORE.target_framework} {CORE.data[KEY_CORE][KEY_FRAMEWORK_VERSION]}), "
                     f"'{CONF_INTERRUPT_PIN}' is a required option for [ethernet]."
                 )
-        if CORE.using_esp_idf and CONF_INTERFACE not in config:
+        if CONF_INTERFACE not in config:
             variant = get_esp32_variant()
             if variant in (
                 VARIANT_ESP32C3,
@@ -262,10 +262,7 @@ SPI_SCHEMA = BASE_SCHEMA.extend(
             cv.Optional(CONF_CLOCK_SPEED, default="26.67MHz"): cv.All(
                 cv.frequency, cv.int_range(int(8e6), int(80e6))
             ),
-            cv.Optional(CONF_INTERFACE): cv.All(
-                cv.only_with_framework("esp-idf"),
-                cv.one_of(*SPI_INTERFACE_MAP.keys()),
-            ),
+            cv.Optional(CONF_INTERFACE): cv.one_of(*SPI_INTERFACE_MAP.keys()),
             # Set default value (SPI_ETHERNET_DEFAULT_POLLING_INTERVAL) at _validate()
             cv.Optional(CONF_POLLING_INTERVAL): cv.All(
                 cv.positive_time_period_milliseconds,
@@ -300,14 +297,7 @@ def _final_validate(config):
     if config[CONF_TYPE] not in SPI_ETHERNET_TYPES:
         return
     if spi_configs := fv.full_config.get().get(CONF_SPI):
-        if CORE.using_esp_idf and CONF_INTERFACE in config:
-            spi_host = SPI_INTERFACE_MAP[config[CONF_INTERFACE]]
-        else:
-            variant = get_esp32_variant()
-            if variant in (VARIANT_ESP32C3, VARIANT_ESP32S2, VARIANT_ESP32S3):
-                spi_host = "SPI2_HOST"
-            else:
-                spi_host = "SPI3_HOST"
+        spi_host = SPI_INTERFACE_MAP[config[CONF_INTERFACE]]
         for spi_conf in spi_configs:
             if (index := spi_conf.get(CONF_INTERFACE_INDEX)) is not None:
                 interface = get_spi_interface(index)

esphome/components/ethernet/ethernet_component.cpp

@@ -385,7 +385,6 @@ void EthernetComponent::dump_config() {
                 "  MOSI Pin: %u\n"
                 "  CS Pin: %u",
                 this->clk_pin_, this->miso_pin_, this->mosi_pin_, this->cs_pin_);
-#ifdef USE_ESP_IDF
   {
     constexpr std::array<char const *const, SPI_HOST_MAX> values{"spi1", "spi2", "spi3"};
     char const *const value{this->interface_ < values.size() ? values[this->interface_] : nullptr};
@@ -393,7 +392,6 @@ void EthernetComponent::dump_config() {
       ESP_LOGCONFIG(TAG, "  Interface: %s", value);
     }
   }
-#endif
 #ifdef USE_ETHERNET_SPI_POLLING_SUPPORT
   if (this->polling_interval_ != 0) {
     ESP_LOGCONFIG(TAG, "  Polling Interval: %lu ms", this->polling_interval_);
@@ -678,9 +676,7 @@ void EthernetComponent::set_cs_pin(uint8_t cs_pin) { this->cs_pin_ = cs_pin; }
 void EthernetComponent::set_interrupt_pin(uint8_t interrupt_pin) { this->interrupt_pin_ = interrupt_pin; }
 void EthernetComponent::set_reset_pin(uint8_t reset_pin) { this->reset_pin_ = reset_pin; }
 void EthernetComponent::set_clock_speed(int clock_speed) { this->clock_speed_ = clock_speed; }
-#ifdef USE_ESP_IDF
-void EthernetComponent::set_interface(SPIInterface interface) { this->interface_ = interface; }
-#endif
+void EthernetComponent::set_interface(spi_host_device_t interface) { this->interface_ = interface; }
 #ifdef USE_ETHERNET_SPI_POLLING_SUPPORT
 void EthernetComponent::set_polling_interval(uint32_t polling_interval) { this->polling_interval_ = polling_interval; }
 #endif

esphome/components/ethernet/ethernet_component.h

@@ -9,8 +9,6 @@
 
 #include "driver/spi_master.h"
 
-using SPIInterface = spi_host_device_t;
-
 #endif  // USE_ESP_IDF
 
 #ifdef USE_ESP32
@@ -78,9 +76,7 @@ class EthernetComponent : public Component {
   void set_interrupt_pin(uint8_t interrupt_pin);
   void set_reset_pin(uint8_t reset_pin);
   void set_clock_speed(int clock_speed);
-#ifdef USE_ESP_IDF
-  void set_interface(SPIInterface interface);
-#endif
+  void set_interface(spi_host_device_t interface);
 #ifdef USE_ETHERNET_SPI_POLLING_SUPPORT
   void set_polling_interval(uint32_t polling_interval);
 #endif
@@ -135,9 +131,7 @@ class EthernetComponent : public Component {
   int reset_pin_{-1};
   int phy_addr_spi_{-1};
   int clock_speed_;
-#ifdef USE_ESP_IDF
-  SPIInterface interface_{SPI_HOST_MAX};  // Default to invalid, will be set based on ESP32 variant
-#endif
+  spi_host_device_t interface_;
 #ifdef USE_ETHERNET_SPI_POLLING_SUPPORT
   uint32_t polling_interval_{0};
 #endif