ARM: configs: stm32: enable ADC driver

ADC driver depends on REGULATOR and IIO that are not yet selected.
Current hardware boards (like stm32f429i-eval) is using fixed
regulators.
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com>

arch/arm/configs/stm32_defconfig

@@ -48,6 +48,8 @@ CONFIG_SERIAL_STM32=y
 CONFIG_SERIAL_STM32_CONSOLE=y
 # CONFIG_HW_RANDOM is not set
 # CONFIG_HWMON is not set
+CONFIG_REGULATOR=y
+CONFIG_REGULATOR_FIXED_VOLTAGE=y
 # CONFIG_USB_SUPPORT is not set
 CONFIG_NEW_LEDS=y
 CONFIG_LEDS_CLASS=y
@@ -56,6 +58,9 @@ CONFIG_LEDS_TRIGGERS=y
 CONFIG_LEDS_TRIGGER_HEARTBEAT=y
 CONFIG_DMADEVICES=y
 CONFIG_STM32_DMA=y
+CONFIG_IIO=y
+CONFIG_STM32_ADC_CORE=y
+CONFIG_STM32_ADC=y
 # CONFIG_FILE_LOCKING is not set
 # CONFIG_DNOTIFY is not set
 # CONFIG_INOTIFY_USER is not set