[media] media: ti-vpe: Use mem-to-mem ioctl helpers

1: Simplify the vpe mem-to-mem driver by using the m2m ioctl
   and vb2 helpers.
2: Align and arranged the v4l2_ioctl_ops.
3: Fixes a typo.
4: Use of_match_ptr() instead of explicitly defining the macro
   to NULL in case CONFIG_OF is not defined.

Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>