net: mtk_eth: add COMPILE_TEST support

Improve the build testing of mtk_eth drivers by enabling them when
COMPILE_TEST is selected. Moreover COMPILE_TEST will be useful
for the driver development.
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mediatek/Kconfig

 # SPDX-License-Identifier: GPL-2.0-only
 config NET_VENDOR_MEDIATEK
 	bool "MediaTek devices"
-	depends on ARCH_MEDIATEK || SOC_MT7621 || SOC_MT7620
+	depends on ARCH_MEDIATEK || SOC_MT7621 || SOC_MT7620 || COMPILE_TEST
 	help
 	  If you have a Mediatek SoC with ethernet, say Y.
 
@@ -10,6 +10,7 @@ if NET_VENDOR_MEDIATEK
 config NET_MEDIATEK_SOC
 	tristate "MediaTek SoC Gigabit Ethernet support"
 	depends on NET_DSA || !NET_DSA
+	select PINCTRL
 	select PHYLINK
 	select DIMLIB
 	help