Revert "d2: add support for variant defconfigs"

This reverts commit c620048d9452187ba48a39892f0711f249dadf50.

Conflicts:
	scripts/kconfig/conf.c

Change-Id: I7880c33bb166bff3175292bc29c108fb96d256f8
d2: commonize everything

* defconfigs
* board files
* all other references to CONFIG_MACH_M2_*
* use VZW as the preferred option
* remove CONFIG_MSM_BAM_DMUX_NOLOCK and set it as default for M2

Change-Id: I47bc15a2782ae6bad72a4ac8e1f4b6a100b64739
Merge changes I47bc15a2,I7880c33b into cm-11.0

* changes:
  d2: commonize everything
  Revert "d2: add support for variant defconfigs"