drm/amd/powerplay/vega20: tell the correct gfx voltage V2

Export the correct gfx voltage by hwmon interface.

V2: update the register naming for consistency

Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/pp: Export registers for read vddc on VI/Vega10

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

drm/amd/include:cleanup vega10 smuio header files.

Cleanup asic_reg/vega10/SMUIO folder.

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