Revert "drm/i915: don't touch the VDD when disabling the panel"

Revert "drm/i915: don't touch the VDD when disabling the panel"

This reverts
commit f87fdb776e7a78beec4c6d3c1552f26e391b1352
Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
Date:   Fri Dec 6 17:32:41 2013 -0200

    drm/i915: don't touch the VDD when disabling the panel

which didn't take into account

commit b7329eb1479aaa16da2237f08cc76bc9d7adcb85
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Sun May 20 17:14:50 2012 +0200

    drm/i915: enable vdd when switching off the eDP panel

and

commit 7b6ce6bd75c74550de5599a35fcd95fe264c1880
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Sun Aug 12 22:17:14 2012 +0200

    drm/i915: reorder edp disabling to fix ivb MacBook Air

Unsurprisingly, various MacBooks failed.

Effectively the same has already been done in drm-intel-next-queued.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=74628
Tested-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>