Revert "mmc: bcm2835: Terminate timeout work synchronously"

The commit 37fefade ("mmc: bcm2835: Terminate timeout work
synchronously") causes lockups in case of hardware timeouts due the
timeout work also calling cancel_delayed_work_sync() on its own.
So revert it.

Fixes: 37fefade ("mmc: bcm2835: Terminate timeout work synchronously")
Cc: stable@vger.kernel.org
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>