[esp8266] Inline arch_get_cpu_cycle_count() and arch_get_cpu_freq_hz()

Both bodies are one-liners:

  arch_get_cpu_cycle_count()  -> esp_get_cycle_count()
  arch_get_cpu_freq_hz()       -> F_CPU

Move them inline in core/hal/hal_esp8266.h:
- esp_get_cycle_count() comes from <core_esp8266_features.h> (now
  pulled into hal_esp8266.h, small ESP8266-only header).
- F_CPU is a -DF_CPU=80000000L compiler flag from the ESP8266 Arduino
  board defs, available without any include.

Drop the cross-platform arch_get_cpu_freq_hz() declaration from the
dispatcher hal.h and add bare decls to hal_esp32.h / hal_libretiny.h /
hal_rp2040.h / hal_host.h / hal_zephyr.h so subsequent per-platform
follow-ups only touch their own platform header.

esphome/components/esp8266/hal.cpp

@@ -97,9 +97,6 @@ void arch_restart() {
   }
 }
 
-uint32_t IRAM_ATTR HOT arch_get_cpu_cycle_count() { return esp_get_cycle_count(); }
-uint32_t arch_get_cpu_freq_hz() { return F_CPU; }
-
 }  // namespace esphome
 
 // Linker wrap: redirect all ::millis() calls (Arduino libs, ISRs) to our accumulator.

esphome/core/hal.h

@@ -31,10 +31,10 @@
 namespace esphome {
 
 // Cross-platform declarations. delayMicroseconds(), arch_feed_wdt(),
-// arch_get_cpu_cycle_count(), arch_init() vary per platform (some inline,
-// some out-of-line) so they live in hal/hal_<platform>.h.
+// arch_get_cpu_cycle_count(), arch_init(), arch_get_cpu_freq_hz() vary
+// per platform (some inline, some out-of-line) so they live in
+// hal/hal_<platform>.h.
 void __attribute__((noreturn)) arch_restart();
-uint32_t arch_get_cpu_freq_hz();
 
 #ifndef USE_ESP8266
 // All non-ESP8266 platforms: PROGMEM is a no-op, so these are direct dereferences.

esphome/core/hal/hal_esp32.h

@@ -43,6 +43,7 @@ __attribute__((always_inline)) inline void arch_feed_wdt() { esp_task_wdt_reset(
 __attribute__((always_inline)) inline uint32_t arch_get_cpu_cycle_count() { return esp_cpu_get_cycle_count(); }
 
 void arch_init();
+uint32_t arch_get_cpu_freq_hz();
 
 }  // namespace esphome
 

esphome/core/hal/hal_esp8266.h

@@ -3,6 +3,7 @@
 #ifdef USE_ESP8266
 
 #include <c_types.h>
+#include <core_esp8266_features.h>
 #include <cstdint>
 #include <pgmspace.h>
 
@@ -59,8 +60,10 @@ __attribute__((always_inline)) inline uint16_t progmem_read_uint16(const uint16_
 __attribute__((always_inline)) inline void delayMicroseconds(uint32_t us) { delay_microseconds_safe(us); }
 __attribute__((always_inline)) inline void arch_feed_wdt() { system_soft_wdt_feed(); }
 __attribute__((always_inline)) inline void arch_init() {}
-
-uint32_t arch_get_cpu_cycle_count();
+// esp_get_cycle_count() declared in <core_esp8266_features.h>; F_CPU is a
+// compiler-driven macro from the ESP8266 Arduino board defs (-DF_CPU=...).
+__attribute__((always_inline)) inline uint32_t arch_get_cpu_cycle_count() { return esp_get_cycle_count(); }
+__attribute__((always_inline)) inline uint32_t arch_get_cpu_freq_hz() { return F_CPU; }
 
 }  // namespace esphome
 

esphome/core/hal/hal_host.h

@@ -23,6 +23,7 @@ void delayMicroseconds(uint32_t us);  // NOLINT(readability-identifier-naming)
 void arch_feed_wdt();
 uint32_t arch_get_cpu_cycle_count();
 void arch_init();
+uint32_t arch_get_cpu_freq_hz();
 
 }  // namespace esphome
 

esphome/core/hal/hal_libretiny.h

@@ -92,6 +92,7 @@ void delayMicroseconds(uint32_t us);  // NOLINT(readability-identifier-naming)
 void arch_feed_wdt();
 uint32_t arch_get_cpu_cycle_count();
 void arch_init();
+uint32_t arch_get_cpu_freq_hz();
 
 }  // namespace esphome
 

esphome/core/hal/hal_rp2040.h

@@ -39,6 +39,7 @@ void delayMicroseconds(uint32_t us);  // NOLINT(readability-identifier-naming)
 void arch_feed_wdt();
 uint32_t arch_get_cpu_cycle_count();
 void arch_init();
+uint32_t arch_get_cpu_freq_hz();
 
 }  // namespace esphome
 

esphome/core/hal/hal_zephyr.h

@@ -23,6 +23,7 @@ void delayMicroseconds(uint32_t us);  // NOLINT(readability-identifier-naming)
 void arch_feed_wdt();
 uint32_t arch_get_cpu_cycle_count();
 void arch_init();
+uint32_t arch_get_cpu_freq_hz();
 
 }  // namespace esphome