Merge patch series "can: mcp251xfd: add XSTBYEN transceiver standby control"

Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com> says:

The MCP251xFD provides a dedicated transceiver standby control function via
the INT0/GPIO0/XSTBY pin, controlled by the XSTBYEN bit in IOCON. When
enabled, the hardware automatically drives the pin low while the controller
is active and high when it enters Sleep mode, allowing automatic standby
control of an external CAN transceiver without software intervention.

This series adds driver support for the XSTBYEN-based transceiver standby
control feature.

Tested on QCS6490 RB3 Gen2 with a PCAN-USB FD adapter: the transceiver is
active in normal mode, CAN communication works correctly, and the pin is
automatically managed across sleep and wake transitions.

Link: https://patch.msgid.link/20260321135031.3107408-1-viken.dadhaniya@oss.qualcomm.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>