This patch adds interface to write pptable for smu.
It's to copy pptable bo in the vram to smc with SMU MSGs such as
SetDriverDramAddr and TransferTableDram2Smu.

v2: add detailed info to describe this function
Signed-off-by: Huang Rui <ray.huang@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>