[media] fsl-viu: small fixes

- Fix an off-by-one index check in vidioc_enum_fmt()
- Fill in the pix.sizeimage field in vidioc_try_fmt_cap()
- Fix an off-by-one index check in vidioc_s_input()

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>