soc: Mediatek: Enable SCPSYS power domain driver by default

If enable Mediatek 8173 SoC, it should also enable power domain
driver. Otherwise access clk subsystem register will fail.
Signed-off-by: Eddie Huang <eddie.huang@mediatek.com>
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>

drivers/soc/mediatek/Kconfig

@@ -23,6 +23,7 @@ config MTK_PMIC_WRAP
 config MTK_SCPSYS
 	bool "MediaTek SCPSYS Support"
 	depends on ARCH_MEDIATEK || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
 	select REGMAP
 	select MTK_INFRACFG
 	select PM_GENERIC_DOMAINS if PM