can: m_can: fix block comment style

This patch fixes the commenting style in the m_can driver.

Fixes: 1be37d3b ("can: m_can: fix periph RX path: use rx-offload to ensure skbs are sent from softirq context")
Fixes: df06fd67 ("can: m_can: m_can_chip_config(): enable and configure internal timestamps")
Link: https://lore.kernel.org/r/20210819111703.599686-2-mkl@pengutronix.de


Cc: Chandrasekar Ramakrishnan <rcsekar@samsung.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>