Workaround to avoid intermittent aux channel failures, per spec change.

v2: Don't mess with cpu dp aux divider (Paulo Zanoni)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
[danvet: Kill spurious tab spotted by Paulo.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>