Statically configured NIC bridge clients must be configured via
<policy...> nodes in the config. Otherwise, the bridge can't answer ARP
requests or route traffic.
The netperf test configures the target Genode system for with
10.0.2.55/24. Also, nic_drv on base-linux uses the virtual ethernet
device 'tap0', which must be configured for the test user and network
address 10.0.2.1/24 on the test host like follows.
tunctl -t tap0 -u <user running test>
ip address add 10.0.2.1/24 dev tap
ip link set tap0 up
Split the netperf run script into 3 ones so that it can be used more easily
in an automated run.
netperf.run - use native nic driver (x86) or usb2.0 (arndale, panda)
netperf_usb30.run - use native nic driver (x86) or usb3.0
netperf_bridge.run - use native nic driver (x86) or usb3.0 (arndale) and bridge
Issue #794
