drm/amdgpu: fix pm sysfs node handling (v2)

Fix typos that prevented them from showing up.

v2: switch other files in addition to pp_clk_voltage

Fixes: 4e01847c ("drm/amdgpu: optimize amdgpu device attribute code")
Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1150


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