drm/i915: Fix printing proper min/min/rpe values in debugfs

This was fumbled while trying to use the cached min/min/rpe values in
the vlv debugfs code.

    This is a regression from

    commit 03af2045


    Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
    Date:   Sat Jun 28 02:03:53 2014 +0300

    drm/i915: Use the cached min/min/rpe values in the vlv debugfs code

Signed-off-by: Deepak S <deepak.s@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>