frontends/va: support yuv 400/444 rt_formats in vaconfig

frontends/va: support yuv 400/444 rt_formats in vaconfig

check if vaprofile supports decode of yuv400 and yuv444 formats
and enable the corresponding rt_formats in vaconfig.

v2: use config->entrypoint as param instead of BITSTREAM (Sil Vilerino)

Signed-off-by: James Zhu <James.Zhu@amd.com>
Signed-off-by: Sathishkumar S <sathishkumar.sundararaju@amd.com>
Reviewed-by: Ruijing Dong <ruijing.dong@amd.com>
Reviewed-by: Boyuan Zhang <Boyuan.Zhang@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18914>