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/configs/odroid-c2_defconfig b/configs/odroid-c2_defconfig
new file mode 100644
index 0000000..a771b20
--- /dev/null
+++ b/configs/odroid-c2_defconfig
@@ -0,0 +1,23 @@
+CONFIG_ARM=y
+CONFIG_ARCH_MESON=y
+CONFIG_MESON_GXBB=y
+CONFIG_TARGET_ODROID_C2=y
+CONFIG_DEFAULT_DEVICE_TREE="meson-gxbb-odroidc2"
+# CONFIG_CMD_BDI is not set
+# CONFIG_CMD_IMI is not set
+# CONFIG_CMD_IMLS is not set
+# CONFIG_CMD_LOADS is not set
+# CONFIG_CMD_FPGA is not set
+# CONFIG_CMD_SOURCE is not set
+# CONFIG_CMD_SETEXPR is not set
+CONFIG_OF_CONTROL=y
+CONFIG_NET_RANDOM_ETHADDR=y
+CONFIG_DM_ETH=y
+CONFIG_ETH_DESIGNWARE=y
+CONFIG_DEBUG_UART=y
+CONFIG_DEBUG_UART_MESON=y
+CONFIG_DEBUG_UART_BASE=0xc81004c0
+CONFIG_DEBUG_UART_CLOCK=24000000
+CONFIG_DEBUG_UART_ANNOUNCE=y
+CONFIG_DEBUG_UART_SKIP_INIT=y
+CONFIG_MESON_SERIAL=y