baremetal-helloworld: set UPSTREAM_CHECK_COMMITS

baremetal-helloworld: set UPSTREAM_CHECK_COMMITS

set UPSTREAM_CHECK_COMMITS to make new commit is reported

Test result(change SRCREV to an old one):
$devtool check-upgrade-status baremetal-helloworld
baremetal-helloworld      0.1             new commits     Alejandro Hernandez <alejandro@enedino.org> db2bf750eaef7fc0832e13ada8291343bbcc3afe

Signed-off-by: Changqing Li <changqing.li@windriver.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>