ARM: dts: imx7-colibri: prepare module device tree for FlexCAN

Prepare FlexCAN use on SODIMM 55/63 178/188. Those SODIMM pins are
compatible for CAN bus use with several modules from the Colibri
family.
Add Better drivestrength and also add flexcan2.

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