drm/radeon: Remove KFD_CIK_SDMA_QUEUE_OFFSET

Leftover from recently removed amdkfd support.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Michel Dänzer <michel@daenzer.net>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>