rbutil uses several components from the utils folder, and can be
considered part of utils too. Having it in a separate folder is an
arbitrary split that doesn't help anymore these days, so merge them.
This also allows other utils to easily use libtools.make without the
need to navigate to a different folder.
Change-Id: I3fc2f4de19e3e776553efb5dea5f779dfec0dc21
Rewrite dualboot in C code instead of assembly. Also properly
handle subtarget and simply Makefile. This should make the
dualboot stub more readable and easier to extend. The new code
also gracefully handles power up from RTC alarm on imx233.
Change-Id: I7c225254b1463a97e76b6cb4de476aa2d2c9d2f9