drm/amdkfd: Fix CU Masking for GFX 9.4.3

We are incorrectly passing the first XCC's MQD when
updating CU masks for other XCCs in the partition. Fix
this by passing the MQD for the XCC currently being
updated with CU mask to update_cu_mask function.

Fixes: fc6efed2 ("drm/amdkfd: Update CU masking for GFX 9.4.3")
Signed-off-by: Mukul Joshi <mukul.joshi@amd.com>
Reviewed-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>