[media] saa7134: Fix crash when device is closed before streamoff

pm_qos_remove_request was not called on video_release, resulting in the PM
core's list of requests being corrupted when the file handle was freed.
This has no immediate symptoms, but later in operation, the kernel will
panic as the PM core dereferences a dangling pointer.

Signed-off-by: Simon Farnsworth <simon.farnsworth@onelan.co.uk>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>