drm/amdgpu: Add kgd kfd interface get_tile_config() v2

v2:
* Removed amdgpu_amdkfd prefix from static functions
* Documented get_tile_config in kgd_kfd_interface.h

Signed-off-by: Yong Zhao <yong.zhao@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>