This removes some dubious functions and replaces them with a simpler, cleaner
API which better describes what the code is doing. Unused code/variables are
removed and comments tweaked.
(Bitbake rev: f1e943aebfb84e98253f3f21646d6765c4fa1d66)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>