drm/amdkfd: Load mqd to hqd in non-HWS mode

This patch fixes a bug in DQM, where the MQD of a newly created compute queue
is not loaded to an HQD slot. As a result, the CP never reads packets from this
queue.

This bug happens only in non-HWS (hardware scheduling) mode. In HWS mode, the
CP is responsible of loading MQDs to HQDs slots.

Signed-off-by: Ben Goz <ben.goz@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>