arm: add initial support for Amlogic P212 based on Meson GXL family

This adds platform code for the Amlogic P212 reference board based on a
Meson GXL (S905X) SoC with the Meson GXL configuration.

This initial submission only supports UART and MMC/SDCard, support for the
internal Ethernet PHY in Work In Progress.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Beniamino Galvani <b.galvani@gmail.com>
diff --git a/configs/p212_defconfig b/configs/p212_defconfig
new file mode 100644
index 0000000..3c57621
--- /dev/null
+++ b/configs/p212_defconfig
@@ -0,0 +1,31 @@
+CONFIG_ARM=y
+CONFIG_ARCH_MESON=y
+CONFIG_MESON_GXL=y
+CONFIG_TARGET_P212=y
+CONFIG_IDENT_STRING=" p212"
+CONFIG_DEFAULT_DEVICE_TREE="meson-gxl-s905x-p212"
+CONFIG_DEBUG_UART=y
+CONFIG_ENV_IS_NOWHERE=y
+# CONFIG_DISPLAY_CPUINFO is not set
+# CONFIG_DISPLAY_BOARDINFO is not set
+# 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_MMC=y
+# CONFIG_CMD_FPGA is not set
+CONFIG_CMD_GPIO=y
+# CONFIG_CMD_SETEXPR is not set
+CONFIG_OF_CONTROL=y
+CONFIG_DM_GPIO=y
+CONFIG_DM_MMC=y
+CONFIG_MMC_MESON_GX=y
+CONFIG_PINCTRL=y
+CONFIG_PINCTRL_MESON_GXL=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
+CONFIG_OF_LIBFDT_OVERLAY=y