drm/amdkfd: PM4 packets change to support GWS

Add a field in map_queues packet to indicate whether
this is a gws control queue. Only one queue per process
can be gws control queue. Change num_gws field in
map_process packet to 7 bits

Signed-off-by: Oak Zeng <Oak.Zeng@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>