drm/i915: Move power well resume earlier

i915_restore_state() -> i915_restore_display() will attempt to
re-disable VGA during resume. So the power well needs to be powered on
before that.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>