misc cleanups

*no need to inherit phone tech makefile anymore
---http://review.cyanogenmod.org/#/c/52265/
*remove unneeded kernel headers
*remove non-CyanogenMod targets from vendorsetup.sh

Change-Id: I6d0a1839e1960873eafba9f4b32ea7ef4faedcb8
recovery: reorganize & cleanup

*Extend recovery init.rc using init.recovery.${ro.hardware}.rc
 instead of replacing it.
*Move binary needed for recovery to prebuilts. Nothing recovery
 specific left to keep separate recovery directory.

Change-Id: Ieb46f8832df04380f08ad3a82b788634d4f606f6