drivers: wifi: Update drivers to use devicetree Kconfig symbol

Update Wifi drivers to use DT_HAS_<compat>_ENABLED Kconfig symbol
to expose the driver and enable it by default based on devicetree.

Signed-off-by: Kumar Gala <galak@kernel.org>
diff --git a/drivers/wifi/esp32/Kconfig.esp32 b/drivers/wifi/esp32/Kconfig.esp32
index 65c544d..628c95e 100644
--- a/drivers/wifi/esp32/Kconfig.esp32
+++ b/drivers/wifi/esp32/Kconfig.esp32
@@ -2,6 +2,8 @@
 
 menuconfig WIFI_ESP32
 	bool "ESP32 SoC WiFi support"
+	default y
+	depends on DT_HAS_ESPRESSIF_ESP32_WIFI_ENABLED
 	depends on !SMP
 	select THREAD_CUSTOM_DATA
 	select WIFI_USE_NATIVE_NETWORKING