media: dt-bindings: media: i2c: Rename ov8856.yaml

Rename 'ov8856.yaml' as 'ovti,ov8856.yaml' and update the MAINTAINERS
file entry accordingly.

All the Omnivision sensor DT bindings have vendor prefix "ovti," to
their file name hence this renaming.

Link: https://lore.kernel.org/linux-media/20220916110955.23757-1-prabhakar.mahadev-lad.rj@bp.renesas.com


Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>