adc: fixed the issue that ADC power is left on after the calibration is done

Also refactor the locks in the adc_common.c file.

components/esp_wifi/src/wifi_init.c

@@ -312,6 +312,8 @@ void wifi_apb80m_release(void)
 #endif //CONFIG_PM_ENABLE
 
 /* Coordinate ADC power with other modules. This overrides the function from PHY lib. */
+// It seems that it is only required on ESP32, but we still compile it for all chips, in case it is
+// called by PHY unexpectedly.
 void set_xpd_sar(bool en)
 {
     if (s_wifi_adc_xpd_flag == en) {