drm/amdkfd: Update mapping if range attributes changed

Change SVM range mapping flags or access attributes don't trigger
migration, if range is already mapped on GPUs we should update GPU
mapping and pass flush_tlb flag true to amdgpu vm.

Change SVM range preferred_loc or migration granularity don't need
update GPU mapping, skip the validate_and_map.

Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>