[COMMON] media: smfc: handle exceptional situations

[COMMON] media: smfc: handle exceptional situations

The driver should be robust under very exceptional situations caused
by unexpected behaviors of processes. Some processes may be suddenly
killed without waiting for the completion of request task in the
driver or H/W. Another processes that is not well-designed so that
they can close the opened device node while forgeting to wait for
the completion of their requested tasks.
Even though processes works unexpectedly, SMFC driver now handles
all exceptional cases with waiting for the H/W's working before
releasing all resources referred by the driver. Other resources that
the driver does not care about is handled by the frameworks such as
videobuf2 and v4l2-mem2mem.

Change-Id: I5ec4c3d91a9328e163658b3732a5ab37de30e73c
Signed-off-by: Cho KyongHo <pullip.cho@samsung.com>