[media] media: Doc s5p-mfc add missing fields to s5p_mfc_dev structure definition

Add missing documentation for s5p_mfc_dev structure definition.
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/s5p-mfc/s5p_mfc_common.h

@@ -292,7 +292,9 @@ struct s5p_mfc_priv_buf {
  * @warn_start:		hardware error code from which warnings start
  * @mfc_ops:		ops structure holding HW operation function pointers
  * @mfc_cmds:		cmd structure holding HW commands function pointers
+ * @mfc_regs:		structure holding MFC registers
  * @fw_ver:		loaded firmware sub-version
+ * risc_on:		flag indicates RISC is on or off
  *
  */
 struct s5p_mfc_dev {