drm/amdgpu: Add new VegaM pci id

commit f6653a0e0877572c87f6dab5351e7bd6b6b7100c upstream.

Add a new pci id.

Reviewed-by: Leo Liu <leo.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>