app/testpmd: merge ports list update functions
app/testpmd: merge ports list update functions

The arrays ports_ids and fwd_ports_ids require the same kind
of update when some ports are removed or added.

The functions update_fwd_ports() and remove_unused_fwd_ports()
are merged in the new function remove_invalid_ports().
The part for adding new port is moved into setup_attached_port().

Signed-off-by: Thomas Monjalon <5f50a84c1fa3bcff146405017f36aec1a10a9e38@monjalon.net>
Acked-by: Bernard Iremonger <233eeff376ad0c06f66f06c5522ea3c4feb30d3b@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk