g3-common: add d855 (intl), vs985 (vzw) and ls990 (spr)

Change-Id: Id20cb8eb89d8f0bd73e781e1abf067fbd9cda7f4
g3: move wifi/bt to variant trees

* LG in their infinite wisdom decided it'd be a good idea to
  ship variantss with different wifi/bt chipsets

Change-Id: If3b14ab444043a2bfc1eaed2df2aa59c3a231c2a