dt-bindings: can: mcp251x: add mcp25625 support

[ Upstream commit 0df82dcd55832a99363ab7f9fab954fcacdac3ae ]

Fully compatible with mcp2515, the mcp25625 have integrated transceiver.

This patch add the mcp25625 to the device tree bindings documentation.

Signed-off-by: Sean Nyekjaer <sean@geanix.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>