arm64: dts: imx8mm: Update i.MX8M Mini Toradex Verdin based Menlo board compatible string

Update the board compatible string such that it matches the YAML DT
schema for validation, add the "toradex,verdin-imx8mm-nonwifi" entry.

Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>