arm64: dts: colibri-imx8x: Move gpio-keys to som level

SODIMM_45 that is connected to "&lsio_gpio3 10" is defined in the
Colibri standard to be a wakeup pin.
Move this to the SoM level device-tree and keep it disabled by default
but do enable it again on the carrier-board.

Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>