Allow a device to define the max number of service groups in init.h

Certain proprieatary binaries (such as tcmd for instance) require
more than 12 supplementary service groups.  By definiing:
TARGET_NR_SVC_SUPP_GIDS := in BoardConfig this can now be changed
per device.

Change-Id: I8f968adc21768ca90232ded7b7e1ffa68dc7ea78

Conflicts:
	init/Android.mk
Init: Allow building of init that is compatible with second init boot

When using second init init has already set up /dev /proc, etc
this will prevent duplicate mount points for those
Define BOARD_USE_NO_DEVFS_SETUP := true to use

Change-Id: I5620664b32e08f39da7ef7c7f9c3824d01f930d6