drm/i915/bxt: update list of PCIIDs

drm/i915/bxt: update list of PCIIDs

BugLink: http://bugs.launchpad.net/bugs/1540390
Add PCIIDs for new versions of the SOC, based on BSpec. Also add the
name of the versions as code comment where this is available. The new
versions don't have any changes visible to the kernel driver.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453989852-13569-1-git-send-email-imre.deak@intel.com
(cherry picked from drm-intel-next commit 985dd4360fdf2533fe48a33a4a2094f2e4718dc0)
Signed-off-by: Timo Aaltonen <timo.aaltonen@canonical.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>