dt-bindings: can: mcp251xfd: add gpio-controller property

dt-bindings: can: mcp251xfd: add gpio-controller property

The mcp251xfd has two pins that can be used as gpio. Add gpio-controller
property to binding description.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Gregor Herburger <gregor.herburger@ew.tq-group.com>
Signed-off-by: Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://patch.msgid.link/20251001091006.4003841-7-viken.dadhaniya@oss.qualcomm.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>