arm64: dts: lx2160a: Add flexcan support

LX2160A supports two flexcan controllers. Add the support.
Enable support further for LX2160A-RDB/QDS.

Signed-off-by: Kuldeep Singh <kuldeep.singh@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>