arm: imx8m: add support for Compulab iot-gate-imx8 (imx8mm-cl-iot-gate)

Add initial support for Compulab iot-gate-imx8 board (imx8mm-cl-iot-gate).
The initial support includes:
 - MMC
 - eMMC
 - I2C
 - FEC
 - Serial console

Signed-off-by: Kirill Kapranov <kirill.kapranov@compulab.co.il>
Signed-off-by: Uri Mashiach <uri.mashiach@compulab.co.il>
Signed-off-by: Valentin Raevsky <valentin@compulab.co.il>
Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>
Cc: Peter Robinson <pbrobinson@gmail.com>
diff --git a/board/compulab/imx8mm-cl-iot-gate/imximage-8mm-lpddr4.cfg b/board/compulab/imx8mm-cl-iot-gate/imximage-8mm-lpddr4.cfg
new file mode 100644
index 0000000..b89092a
--- /dev/null
+++ b/board/compulab/imx8mm-cl-iot-gate/imximage-8mm-lpddr4.cfg
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2021 NXP
+ */
+
+#define __ASSEMBLY__
+
+BOOT_FROM	sd
+LOADER		mkimage.flash.mkimage	0x7E1000