mmc: sh_mmcif: switch to completion, fix flags

In sh_mmcif.c an event is used as a completion, switch over. When a
wait_for_completion*_timeout() returns, it suffices to check the remaining
time, setting an additional flag before waking up the waiting task only reduces
the race window, but does not eliminate it. This patch switches the driver to
use a completion to signal an interrupt, the only case, when an interrupt
should not wake up the waiter, is when an automatic CMD12 completes. Also fix
MODULE_ALIAS.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>