linux-phytec-fsl

drm/amd/powerplay: Mark functions of ppevvmath.h static

This introduces some warnings due to unused functions, that are
deleted in the following commit.

Signed-off-by: Nils Wallménius <nils.wallmenius@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>