drm/i915/skl: send opregion_nofify_adapter(PCI_D1) instead of PCI_D3

I was told that the "repurposed D1 definition" is still valid for SKL.
It is BDW that is special due to its hotplug bug, so let's
special-case BDW instead of HSW.

Cc: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>