imx: add i.MX8QXP MEK board support

Add i.MX8QXP MEK board support
Enabled pinctrl/clk/power-domain/mmc/i2c/fec driver.
Added README file.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
diff --git a/board/freescale/imx8qxp_mek/Kconfig b/board/freescale/imx8qxp_mek/Kconfig
new file mode 100644
index 0000000..b67300d
--- /dev/null
+++ b/board/freescale/imx8qxp_mek/Kconfig
@@ -0,0 +1,14 @@
+if TARGET_IMX8QXP_MEK
+
+config SYS_BOARD
+	default "imx8qxp_mek"
+
+config SYS_VENDOR
+	default "freescale"
+
+config SYS_CONFIG_NAME
+	default "imx8qxp_mek"
+
+source "board/freescale/common/Kconfig"
+
+endif