drm/amd/pm: optimize the link width/speed retrieving V2

By using the information provided by PMFW when available.

V2: put those structures shared around SMU V11 ASICs in
    smu_v11_0.h

Signed-off-by: Evan Quan <evan.quan@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>