arm: add initial support for Amlogic P212 based on Meson GXL family

This adds platform code for the Amlogic P212 reference board based on a
Meson GXL (S905X) SoC with the Meson GXL configuration.

This initial submission only supports UART and MMC/SDCard, support for the
internal Ethernet PHY in Work In Progress.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Beniamino Galvani <b.galvani@gmail.com>
diff --git a/arch/arm/mach-meson/Kconfig b/arch/arm/mach-meson/Kconfig
index af3be59..d4bd230 100644
--- a/arch/arm/mach-meson/Kconfig
+++ b/arch/arm/mach-meson/Kconfig
@@ -9,6 +9,15 @@
 	  The Amlogic Meson GXBaby (S905) is an ARM SoC with a
 	  quad-core Cortex-A53 CPU and a Mali-450 GPU.
 
+config MESON_GXL
+	bool "Support Meson GXL"
+	select ARM64
+	select DM
+	select DM_SERIAL
+	help
+	  The Amlogic Meson GXL (S905X and S905X) is an ARM SoC with a
+	  quad-core Cortex-A53 CPU and a Mali-450 GPU.
+
 if MESON_GXBB
 
 config TARGET_ODROID_C2
@@ -20,6 +29,17 @@
 
 endif
 
+if MESON_GXL
+
+config TARGET_P212
+	bool "P212"
+	help
+	  P212 is a reference dessign board based on Meson GXL S905X SoC
+	  with 2 GiB of RAM, Ethernet, HDMI, 2 USB, micro-SD slot,
+	  eMMC, IR receiver, CVBS+Audio jack and a SDIO WiFi module.
+
+endif
+
 config SYS_SOC
 	default "meson"
 
@@ -28,4 +48,6 @@
 
 source "board/amlogic/odroid-c2/Kconfig"
 
+source "board/amlogic/p212/Kconfig"
+
 endif