arm: Add Khadas VIM support based on Meson GXL family

This adds platform code for the Khadas VIM board based on a
Meson GXL (S905X) SoC with the Meson GXL configuration.

This initial submission supports UART, MMC/SDCard and Ethernet with the
Internal RMII PHY.

The meson-gxl-s905x-khadas-vim.dts is synchronised from the linux 4.13
stable tree as of 4.13.8.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
diff --git a/arch/arm/mach-meson/Kconfig b/arch/arm/mach-meson/Kconfig
index ca08dc3..0350787 100644
--- a/arch/arm/mach-meson/Kconfig
+++ b/arch/arm/mach-meson/Kconfig
@@ -45,6 +45,13 @@
 	  with 2 GiB of RAM, Ethernet, HDMI, 4 USB, micro-SD slot,
 	  eMMC, IR receiver and a 40-pin GPIO header.
 
+config TARGET_KHADAS_VIM
+	bool "KHADAS-VIM"
+	help
+	  Khadas VIM is a single board computer based on Meson GXL
+	  with 2 GiB of RAM, Ethernet, HDMI, 4 USB, micro-SD slot,
+	  eMMC, IR receiver and a 40-pin GPIO header.
+
 endif
 
 config SYS_SOC
@@ -59,4 +66,6 @@
 
 source "board/amlogic/libretech-cc/Kconfig"
 
+source "board/amlogic/khadas-vim/Kconfig"
+
 endif