init: Support for emmc boot and init.target.rc

 * Via CodeAurora

Change-Id: Iaa9ed356574f364d8061e8941cffc3d458efc603
init: Set the "ro.boot.emmc" property

 * QC switched to this from the old "ro.emmc" property.
 * Set both values since many things depend on this.

Change-Id: I958dbb13b08bd576ad16318683a0eac45dfc6fee
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
Signed-off-by: dhacker29 <davidhackerdvm@gmail.com>

Conflicts:
	init/Android.mk