media: s5p-mfc: Add support for HEVC encoder

Add HEVC encoder support and necessary registers, V4L2 CIDs,
and hevc encoder parameters

Signed-off-by: Smitha T Murthy <smitha.t@samsung.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>