media: rcar-vin: rcar-dma: Fix setting VNIS_REG for RAW8 formats

pixelformat in vin priv structure holds V4L2_PIX_FMT_* and not
MEDIA_BUS_FMT_* so make sure we check against V4L2_PIX_FMT_* formats
while setting the VNIS_REG.

Fixes: 8c3e0f67 ("media: rcar-vin: Extend RAW8 support to all RGB layouts")
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>