media: rkvdec: Add HEVC support for the VDPU383 variant

media: rkvdec: Add HEVC support for the VDPU383 variant

The VDPU383 decoder is used on the RK3576 SoC and has support for HEVC.

This patch also moves some functions to a common rkvdec-hevc-common.c
file and adds a specific scaling matrix flatten function.

The fluster score for JCT-VC-HEVC_V1 is 146/147.

Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>