Add Toradex Verdin IMX8MM Mallow carrier board support. Mallow is a
low-cost carrier board in the Verdin family with a small form factor and
build for volume production making it ideal for industrial and embedded
applications.

https://www.toradex.com/products/carrier-board/mallow-carrier-boardSigned-off-by: Joao Paulo Goncalves <joao.goncalves@toradex.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>