radeon/vcn: reset the decode flags from message buffer

This flag was never used by VCN previously, and now
it's used for feature that is not applied to us.

Signed-off-by: Leo Liu <leo.liu@amd.com>
Reviewed-by: Boyuan Zhang <boyuan.zhang@amd.com>
Reviewed-by: James Zhu <James.Zhu@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5501>
1 file changed