drm/amdgpu: Retrieve CE count from ce_count_lo_chip in EccInfo table

Retrieve correctable error count from ce_count_lo_chip instead of
mca_umc_status.

Signed-off-by: Candice Li <candice.li@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>