mmc: Convert from tasklet to BH workqueue

mmc: Convert from tasklet to BH workqueue

The only generic interface to execute asynchronously in the BH context is
tasklet; however, it's marked deprecated and has some design flaws. To
replace tasklets, BH workqueue support was recently added. A BH workqueue
behaves similarly to regular workqueues except that the queued work items
are executed in the BH context.

This patch converts drivers/mmc/* from tasklet to BH workqueue.

Based on the work done by Tejun Heo <tj@kernel.org>

Tested-by: Christian Loehle <christian.loehle@arm.com>
Tested-by: Aubin Constans <aubin.constans@microchip.com>
Acked-by: Aubin Constans <aubin.constans@microchip.com>
Acked-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Christian Loehle <christian.loehle@arm.com>
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Link: https://lore.kernel.org/r/20240701100736.4001658-1-allen.lkml@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>