dt-bindings: media: s5p-mfc: Add mfcv12 variant

Add Tesla FSD MFC(MFC v12) compatible.

Cc: linux-fsd@tesla.com
Signed-off-by: Aakarsh Jain <aakarsh.jain@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>