drm/amdgpu: Avoid FRU EEPROM access on APU

FRU EEPROM access is not valid for APU devices.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Yang Wang <kevinyang.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>