g3: add d850 and d855 defconfigs

Change-Id: Iaed06660e09ca51251fa53c1be8c3121aece41c4
d850: sync defconfig back to stock

Change-Id: I24f47e0a383487e3f3c309d5e7466ee98e80b095
d852: add initial defconfig

Change-Id: I12042ceca137e3a25dd27034129b7afc56ef1892