modules: update routing

e294a22 batman-adv: Refresh patches with quilt
519ef4a batman-adv: Merge bugfixes from 2021.2
8d93475 olsrd: add filtergw plugin
76a7bc7 olsrd: update to 2021-06-21
3912935 olsrd: use SPDX
69e2fe6 bird2: Fix bus error on OSPF on IPQ806X