drm/amdgpu: add ta firmware load for green-sardine

[Why]
In preparation to enabling hdcp on green sardine.

[How]
Add green-sardine ta f/w loading in psp_v12

Signed-off-by: Roman Li <roman.li@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>