drm/amdgpu: distinguish rlc fw for different SKU

For some SKU, rlc firmware should use different one
compared with the normal rlc firmware.

Signed-off-by: Likun Gao <Likun.Gao@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>