kern-tools: fixes (branching,buildall) + cleanups (checkpoint,cleaner)

kern-tools: fixes (branching,buildall) + cleanups (checkpoint,cleaner)

Updating the kern-tools SRCREV to pickup a collection of bug fixes
and cleanups:

  75e71c3 kgit-config-cleaner: add -k <keep option>
  02be3b5 buildall: switch back to scc driven processing
  c7101db kern-tools: support flexible branching
  e2d06bd kern-tools: Remove superfluous references to "defconfig" from the "createme" script.
  e693754 kgit-checkpoint: fix verify_branch variable name typo
  ee67a7b kgit-config-cleaner: fix redefintion processing

(From OE-Core rev: 70885a105bc16411ff57e3023b33656685cc2bab)

Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>