defconfigs: use a commonized defconfig for d2

Change-Id: Ieebb1fbf7bca2480257cf6477f62a4844aa54066
d2: add support for variant defconfigs

* shamelessly kanged from jf

Change-Id: I86a538f16bbb91dcc9366ed42a35a6451500403d
defconfigs: fix up for selinux dependencies

Change-Id: Ideccb992ebe87d9531bba41239f5bd309103d130
Merge changes Ideccb992,I86a538f1,Ieebb1fbf into cm-10.1

* changes:
  defconfigs: fix up for selinux dependencies
  d2: add support for variant defconfigs
  defconfigs: use a commonized defconfig for d2