drm/amdgpu: Add more FRU field information

Add support to read Manufacturer Name and FRU File Id fields. Also add
sysfs device attributes for external usage.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>