drm/amdgpu/vcn4: Fix IB parsing with multiple engine info packages

commit 2b10cb58 upstream.

There can be multiple engine info packages in one IB and the first one
may be common engine, not decode/encode.
We need to parse the entire IB instead of stopping after finding first
engine info.

Signed-off-by: David Rosca <david.rosca@amd.com>
Reviewed-by: Leo Liu <leo.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit dc8f9f0f)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>