arm: Add LibreTech CC support based on Meson GXL family

This adds platform code for the Libre Computer CC "Le Potato" 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-libretech-cc.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/board/amlogic/libretech-cc/Kconfig b/board/amlogic/libretech-cc/Kconfig
new file mode 100644
index 0000000..7a6f916
--- /dev/null
+++ b/board/amlogic/libretech-cc/Kconfig
@@ -0,0 +1,12 @@
+if TARGET_LIBRETECH_CC
+
+config SYS_BOARD
+	default "libretech-cc"
+
+config SYS_VENDOR
+	default "amlogic"
+
+config SYS_CONFIG_NAME
+	default "libretech-cc"
+
+endif