Revert "Add 'BOARD_MKBOOTIMG_ARGS'"

This reverts commit 9c21704a1afe5b4942a8fd7ab4d41c708f5f2588.
Merge branch 'android-4.4' of https://github.com/MerkMod-ARMv6/android_build into android-4.4

Conflicts:
	core/Makefile