drm/amdgpu: update default voltage for boot od table for navi1x

It needed to be updated as well so it will show the proper values
if you reset to the defaults.

Bug: https://gitlab.freedesktop.org/drm/amd/issues/1020


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