commit 6b57f20c upstream.

Some hawaii cards use a different method to fetch the
voltage info from the vbios.

bug:
https://bugs.freedesktop.org/show_bug.cgi?id=74250Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>