arm64: add basic Kconfig symbols for i.MX8

Add basic Kconfig symbols to make the MXC architecture available
in the ARM64 world.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/Kconfig.platforms

@@ -142,6 +142,14 @@ config ARCH_MVEBU
 	   - Armada 7K SoC Family
 	   - Armada 8K SoC Family
 
+config ARCH_MXC
+	bool "ARMv8 based NXP i.MX SoC family"
+	select ARM64_ERRATUM_843419
+	select ARM64_ERRATUM_845719
+	help
+	  This enables support for the ARMv8 based SoCs in the
+	  NXP i.MX family.
+
 config ARCH_QCOM
 	bool "Qualcomm Platforms"
 	select GPIOLIB