drm/amd: Add get_local_mem_info to KGD-KFD interface

drm/amd: Add get_local_mem_info to KGD-KFD interface

Add get_local_mem_info which provides more information about local
memory than get_vmem_size:
- public and private framebuffer size
- memory clock

Signed-off-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Signed-off-by: Ben Goz <ben.goz@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>