handle dpdk port "siblings"

[david-marchand]

When releasing a DPDK port and asking for detaching/freeing its associated HW resources, care must be taken not to break port "siblings" that were sharing those HW resources.

See testpmd or OVS:
https://git.dpdk.org/dpdk/tree/app/test-pmd/testpmd.c#n3674
https://github.com/openvswitch/ovs/blob/main/lib/netdev-dpdk.c#L1747

[christophefontaine]

Which hardware relies on siblings ?
I'd like to test rjarry/grout@main...christophefontaine:grout:issue_40