drm/amd/powerplay: move Watermarks_t uses into asic level

This patch moves the rest of Watermarks_t uses into asic level. It's to avoid
the conflicts with different asic.

Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Kevin Wang <kevin1.wang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>