BugLink: http://bugs.launchpad.net/bugs/1540390

This reverts

commit 4eddaeec
Author: Lukas Wunner <lukas@wunner.de>
Date:   Mon Jan 11 20:09:20 2016 +0100

    drm/i915: Switch DDC when reading the EDID

which we don't need for i915_bpo.
Signed-off-by: Timo Aaltonen <timo.aaltonen@canonical.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>