drm/amd/pp: Remove duplicate code in vega12_hwmgr.c

use smu_helper function smu_set_watermarks_for_clocks_ranges
in vega12_set_watermarks_for_clocks_ranges.

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>