drm/amd/powerplay: add interface to init smc tables (v2)

This patch adds interface to init smc tables for smu. It is to create smu_table
structure, and init smc tables such as TABLE_PPTABLE, TABLE_WATERMARKS,
TABLE_SMU_METRICS, and etc.

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>