Extension boards can be added to Compulab's iot-gate-imx8mm.
We implement extension board manager for detecting the extension
boards.
Signed-off-by: Uri Mashiach <uri.mashiach@compulab.co.il>
Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>
Cc: uboot-imx <uboot-imx@nxp.com>