drm/amdgpu/gfx9: adjust mqd allocation size

To allocate additional space for the dynamic cu masks.
Confirmed with the hw team that we only need 1 dword
for the mask.  The mask is the same for each SE so
you only need 1 dword.

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