can: flexcan: Ack wakeup interrupt separately

As FLEXCAN_ESR_ALL_INT is for all bus errors and state change IRQ
sources, strictly speaking FLEXCAN_ESR_WAK_INT does not belong to these.
So add wakeup interrupt ack separately to existing ack of the
interrupts.

Suggested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Link: https://lore.kernel.org/r/20191204113249.3381-3-qiangqing.zhang@nxp.com


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