drm/amdkfd: fix redundant MQD iterations in GFX v12.1

drm/amdkfd: fix redundant MQD iterations in GFX v12.1

The init_mqd_v12_1 function and its sub-call update_mqd_v12_1 both independently
iterate over XCC-specific MQDs. This nested iteration is redundant and can cause
MQDs in different queues to be overwritten. This patch removes the duplicate
loop logic to prevent queue corruption.

Fixes: 01bbc4a4b947 ("drm/amdkfd: Add MQD manager for GFX 12.1.0")
Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>