amdgpu/pp: remove ci_smc/smumgr split.

This split serves no purpose, and we can make a bunch of functions
static now.

There are lots of cases of this sort of split in the powerplay code,
please start cleaning them up. Ideally the function table is in the
same file as all the implementations used in it.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>