drm/amdgpu: add ip block number prints

User is able to follow the ip block number to write the ip_block_mask for
selecting the one which user would like to enable.

Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>