boards: amlogic: Add FriendlyElec NanoPi K2 board support

This adds platform code for the FriendlyElec NanoPi K2 board based on a
Meson GXBB (S905) SoC with the Meson GXBB configuration.

This initial submission only supports:
- UART
- MMC/SDCard
- Ethernet
- Reset Controller
- Clock controller

Cc: Yuefei Tan <yftan@friendlyarm.com>
Signed-off-by: Thomas McKahan <tonymckahan@gmail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
diff --git a/arch/arm/mach-meson/Kconfig b/arch/arm/mach-meson/Kconfig
index 9a06ccc..cc3383a 100644
--- a/arch/arm/mach-meson/Kconfig
+++ b/arch/arm/mach-meson/Kconfig
@@ -29,6 +29,12 @@
 	  with 2 GiB of RAM, Gigabit Ethernet, HDMI, 4 USB, micro-SD
 	  slot, eMMC, IR receiver and a 40-pin GPIO header.
 
+config TARGET_NANOPI_K2
+	bool "NANOPI_K2"
+	help
+	  NANOPI_K2 is a single board computer based on Meson GXBaby
+	  with 2 GiB of RAM, Gigabit Ethernet,AP6212 Wifi, HDMI, 4 USB,
+	  micro-SD slot, eMMC, IR receiver and a 40-pin GPIO header.
 endif
 
 if MESON_GXL
@@ -64,6 +70,8 @@
 
 source "board/amlogic/odroid-c2/Kconfig"
 
+source "board/amlogic/nanopi-k2/Kconfig"
+
 source "board/amlogic/p212/Kconfig"
 
 source "board/amlogic/libretech-cc/Kconfig"