owners: add rhel-sst-networking
Some of these have maintainers from multiple SSTs and will likely get an additional SST added.
Note that for "TC subsystem", the maintainer (Ivan) is from sst-nic-rdma. I'm still adding sst-networking to that entry for clarity, since tc is also matched by "NETWORKING [GENERAL]" and is a shared responsibility.
Signed-off-by: Jiri Benc jbenc@redhat.com