media: hantro: Allows luma and chroma depth to be different

Luma and chroma depth are set on different hardware registers.
Even if they aren't identical the bitstream can be compliant
to HEVC specifications and decoded by the hardware.

With this patch TSUNEQBD_A_MAIN10_Technicolor_2 conformance test
is successfully decoded.

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