Revert "ota: Allow devices to skip generation of recovery-from-boot.p"

This reverts commit 651987c5f2f78207edebdd821d1700a0464fdfb5.

Conflicts:
	core/Makefile
	tools/releasetools/ota_from_target_files

Change-Id: I09f489a1cbb313dadd8de24d94c9f187b1ef7629