drm/amd/pm: Get xgmi link status for XGMI_v_6_4_0

Get XGMI_v_6_4_0 link status and populate it to metrics v1_7 for
SMU_v_13_0_6

v2: Get link status register value for each soc from separate
function (Lijo)

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