drm/i915: apply the PCI_D0/D3 hibernation workaround everywhere on pre GEN6

drm/i915: apply the PCI_D0/D3 hibernation workaround everywhere on pre GEN6

commit da2bc1b9db3351addd293e5b82757efe1f77ed1d
Author: Imre Deak <imre.deak@intel.com>
Date:   Thu Oct 23 19:23:26 2014 +0300

    drm/i915: add poweroff_late handler

introduced a regression on old platforms during hibernation. A workaround was
added in

commit ab3be73fa7b43f4c3648ce29b5fd649ea54d3adb
Author: Imre Deak <imre.deak@intel.com>
Date:   Mon Mar 2 13:04:41 2015 +0200

    drm/i915: gen4: work around hang during hibernation

using an explicit blacklist for the GENs/BIOS vendors where the issue was
reported. Later there we had reports of the same failure on platforms not on
this list.

To my best knowledge the correct thing to do is still to put the device to PCI
D3 state during hibernation, see [1] and [2] for the reasons. This also aligns
with our future plans to unify more the runtime and system suspend/resume
paths. Since an exact blacklist seems to be impractical (multiple GENs and
BIOS vendors are affected) apply the workaround on everything pre GEN6.

[1] http://lists.freedesktop.org/archives/intel-gfx/2015-February/060710.html
[2] https://lkml.org/lkml/2015/6/22/274

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=95061
Reported-by: Ilya Tumaykin <itumaykin@gmail.com>
Reported-by: Dirk Griesbach <spamthis@freenet.de>
Reported-by: Pavel Machek <pavel@ucw.cz>
Reported-by: Mikko Rapeli <mikko.rapeli@iki.fi>
Tested-by: Mikko Rapeli <mikko.rapeli@iki.fi>
Reported-by: Paul Bolle <pebolle@tiscali.nl>
CC: stable@vger.kernel.org
Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>