By this, we can avoid to pass in the VRAM address on every table
transferring. That puts extra unnecessary traffics on SMU on
some cases(e.g. polling the amdgpu_pm_info sysfs interface).

V2: document what the driver table is for and how it works
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>