arm64: Kconfig: Introduce CONFIG_ARCH_APPLE

This adds a Kconfig option to toggle support for Apple ARM SoCs.
At this time this targets the M1 and later "Apple Silicon" Mac SoCs.
Signed-off-by: Hector Martin <marcan@marcan.st>

arch/arm64/Kconfig.platforms

@@ -36,6 +36,13 @@ config ARCH_ALPINE
 	  This enables support for the Annapurna Labs Alpine
 	  Soc family.
 
+config ARCH_APPLE
+	bool "Apple Silicon SoC family"
+	select APPLE_AIC
+	help
+	  This enables support for Apple's in-house ARM SoC family, starting
+	  with the Apple M1.
+
 config ARCH_BCM2835
 	bool "Broadcom BCM2835 family"
 	select TIMER_OF

arch/arm64/configs/defconfig

@@ -31,6 +31,7 @@ CONFIG_ARCH_ACTIONS=y
 CONFIG_ARCH_AGILEX=y
 CONFIG_ARCH_SUNXI=y
 CONFIG_ARCH_ALPINE=y
+CONFIG_ARCH_APPLE=y
 CONFIG_ARCH_BCM2835=y
 CONFIG_ARCH_BCM4908=y
 CONFIG_ARCH_BCM_IPROC=y