kern-tools: fix forced branching

kern-tools: fix forced branching

commit 7a79f7412 [linux-yocto: make KBRANCH the exception and not the rule]
ensures that a request branch is always built. The implementation of this
guarantee is a branch switch before the build starts. But that switch may
be before all patches are applied. If the proper routines are not called,
no patches can be applied to the tree.

Updating the SRCREV to pickup this fix:

    updateme: use branch command when forcing branch switches

    When forcing a branch switch to the desired branch we should be
    using the proper 'branch' command. Since without this call, the
    proper variables will not be set, and patches can't be applied
    to the tree.

(From OE-Core rev: bede3086cb9ab0f79fb7775528b646817b2b9af0)

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