drm/amdkfd: decrement queue count on mes queue destroy

Queue count should decrement on queue destruction regardless of HWS
support type.

Signed-off-by: Jonathan Kim <jonathan.kim@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>