[media] s5p-mfc: make queue cleanup code common

Code for queue cleanup has nothing specific to hardware version.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>