KBRANCH_DEFAULT is no longer used, so we can remove it from all
recipes (and it won't be missed).
(From OE-Core rev: e631fc989b08873f559c5927117301294f04298c)
Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>