media: hantro: handle V4L2_PIX_FMT_HEVC_SLICE control

Make sure that V4L2_PIX_FMT_HEVC_SLICE is correctly handled by the driver.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Reviewed-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>