can: m_can: Return ERR_PTR on error in allocation

can: m_can: Return ERR_PTR on error in allocation

We have more detailed error values available, return them in the core
driver and the calling drivers to return proper errors to callers.

Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Reviewed-by: Kendall Willis <k-willis@ti.com>
Signed-off-by: Markus Schneider-Pargmann (TI.com) <msp@baylibre.com>
Link: https://patch.msgid.link/20251001-topic-mcan-wakeup-source-v6-12-v10-3-4ab508ac5d1e@baylibre.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>