[nrf52] allow to build for non nrf52840 boards (#17373)

Co-authored-by: Jonathan Swoboda <154711427+swoboda1337@users.noreply.github.com>

esphome/components/nrf52/__init__.py

@@ -233,7 +233,7 @@ CONFIG_SCHEMA = cv.All(
             ),
             cv.Optional(KEY_BOOTLOADER): cv.one_of(*BOOTLOADERS, lower=True),
             cv.Optional(CONF_DFU): _dfu_schema,
-            cv.Optional(CONF_DCDC, default=True): cv.boolean,
+            cv.Optional(CONF_DCDC): cv.boolean,
             cv.Optional(CONF_REG0): cv.Schema(
                 {
                     cv.Required(CONF_VOLTAGE): cv.All(
@@ -367,16 +367,17 @@ async def to_code(config: ConfigType) -> None:
     if dfu_config := config.get(CONF_DFU):
         CORE.add_job(_dfu_to_code, dfu_config)
     framework_ver: cv.Version = CORE.data[KEY_CORE][KEY_FRAMEWORK_VERSION]
-    if framework_ver < cv.Version(2, 9, 2):
-        zephyr_add_prj_conf("BOARD_ENABLE_DCDC", config[CONF_DCDC])
-    else:
-        zephyr_add_overlay(
-            f"""
-                &reg1 {{
-                    regulator-initial-mode = <{"NRF5X_REG_MODE_DCDC" if config[CONF_DCDC] else "NRF5X_REG_MODE_LDO"}>;
-                }};
-            """
-        )
+    if CONF_DCDC in config:
+        if framework_ver < cv.Version(2, 9, 2):
+            zephyr_add_prj_conf("BOARD_ENABLE_DCDC", config[CONF_DCDC])
+        else:
+            zephyr_add_overlay(
+                f"""
+                    &reg1 {{
+                        regulator-initial-mode = <{"NRF5X_REG_MODE_DCDC" if config[CONF_DCDC] else "NRF5X_REG_MODE_LDO"}>;
+                    }};
+                """
+            )
 
     if reg0_config := config.get(CONF_REG0):
         value = VOLTAGE_LEVELS.index(reg0_config[CONF_VOLTAGE])

tests/components/nrf52/test.nrf52-microbit.yaml

@@ -0,0 +1 @@
+nrf52:

tests/test_build_components/build_components_base.nrf52-microbit.yaml

@@ -0,0 +1,16 @@
+esphome:
+  name: componenttestnrf52
+  friendly_name: $component_name
+
+nrf52:
+  board: bbc_microbit
+
+logger:
+  level: VERY_VERBOSE
+  hardware_uart: UART0
+
+packages:
+  component_under_test: !include
+    file: $component_test_file
+    vars:
+      component_test_file: $component_test_file