drm/amdkfd: use user_gpu_id for svm ranges

Currently the SVM ranges use actual_gpu_id but with Checkpoint Restore
support its possible that the SVM ranges can be resumed on another node
where the actual_gpu_id may not be same as the original (user_gpu_id)
gpu id. So modify svm code to use user_gpu_id.

Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>