radvd: update to 1.9.8

Update radvd to version 1.9.8

* remove change-scanner-dependency.patch which is merged
* add 'status' subcommand for radvd.init

Signed-off-by: Kai Kang <kai.kang@windriver.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>