Backport #969 from trunk:
Rebuild the kconfig stuff on kconfig source change.

/branches/1.2/kconfig/kconfig.mk | 14 12 2 0 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)

 reporter_name="Alexander BIGGA"

 reporter_url="http://sourceware.org/ml/crossgcc/2008-06/msg00031.html"