can: m_can: Batch acknowledge transmit events

Transmit events from the txe fifo can be batch acknowledged by
acknowledging the last read txe fifo item. This will save txe_count
writes which is important for peripheral chips.

Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
Link: https://lore.kernel.org/all/20221206115728.1056014-7-msp@baylibre.com


Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>