drm/radeon/si: drop cg_update from dpm code

I'm not entirely sure this is required and it won't work
with the dpm restructing anyway.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --cc drivers/gpu/drm/radeon/si.c
Simple merge

diff --cc drivers/gpu/drm/radeon/si_dpm.c
Simple merge