ARM64: Enable Amlogic Meson GXBaby platform

Provide the ARCH_MESON Kconfig symbol to allow enabling existing serial
and i2c drivers.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Carlo Caione <carlo@endlessm.com>
diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms
index 21074f6..c900e1708 100644
--- a/arch/arm64/Kconfig.platforms
+++ b/arch/arm64/Kconfig.platforms
@@ -48,6 +48,11 @@
 	help
 	  Support for Mediatek MT65xx & MT81xx ARMv8 SoCs
 
+config ARCH_MESON
+	bool "Amlogic Platforms"
+	help
+	  This enables support for the Amlogic S905 SoCs.
+
 config ARCH_QCOM
 	bool "Qualcomm Platforms"
 	select PINCTRL