drm/amdgpu/gfx10: add support for wks firmware loading

load different cp firmware according to the DID and RID

Reviewed-by: Feifei Xu <Feifei.Xu@amd.com>
Signed-off-by: Tianci.Yin <tianci.yin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>