[media] s5p-mfc: clear 'enter_suspend' flag if suspend fails

The enter_suspend flag is set after we enter mfc suspend function but if
suspend fails after that due to any reason (like hardware timeout etc),
this flag must be cleared before returning an error. Otherwise, this
flag never gets cleared and the MFC suspend will always return an error
on subsequent tries. If clock off fails, disable hw_lock also.

Signed-off-by: Prathyush K <prathyush.k@samsung.com>
Signed-off-by: Kiran AVND <avnd.kiran@samsung.com>
Signed-off-by: Arun Kumar K <arun.kk@samsung.com>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>