devtool: gitsm:// should be handled same as git:// in upgrades

Signed-off-by: Alexander Kanavin <alex.kanavin@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit e7076f17)
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>