dt-bindings: can: xilinx_can: add Xilinx CAN FD 2.0 bindings

Add compatible string and new attributes to support the Xilinx CAN
FD 2.0.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>