arm: add initial support for Amlogic Meson and ODROID-C2

This adds platform code for the Amlogic Meson GXBaby (S905) SoC and a
board definition for ODROID-C2. This initial submission only supports
UART and Ethernet (through the existing Designware driver). DTS files
are the ones submitted to Linux arm-soc for 4.7 [1].

[1] https://patchwork.ozlabs.org/patch/603583/

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index d516345..ecd1887 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -50,6 +50,7 @@
 machine-$(CONFIG_ARCH_KEYSTONE)		+= keystone
 # TODO: rename CONFIG_KIRKWOOD -> CONFIG_ARCH_KIRKWOOD
 machine-$(CONFIG_KIRKWOOD)		+= kirkwood
+machine-$(CONFIG_ARCH_MESON)		+= meson
 machine-$(CONFIG_ARCH_MVEBU)		+= mvebu
 # TODO: rename CONFIG_TEGRA -> CONFIG_ARCH_TEGRA
 # TODO: rename CONFIG_ORION5X -> CONFIG_ARCH_ORION5X