config/switch: populate a "stats" section

[d-k-c]

Switches can report statistics through ethtool -S <ifname>, but they use different names for the same statistics. So we must keep a mapping of these names.

For starter, it would be great to have mappings for the following statistics under a stats section:

• rx_broadcast
• rx_multicast
• rx_octets
• rx_packets
• rx_unicast
• tx_broadcast
• tx_multicast
• tx_octets
• tx_packets
• tx_unicast
• rx_broadcast
• rx_multicast

So conf/switch/example-switch.cfg would look like this:

[stats]
rx_broadcast = "RxBroadcast"
rx_multicast = "RxMulticast"
rx_octets = "RxOctets"
rx_packets = "RxPackets"
rx_unicast = "RxUnicast"
tx_broadcast = "TxBroadcast"
tx_multicast = "TxMulticast"
tx_octets = "TxOctets"
tx_packets = "TxPackets"
tx_unicast = "TxUnicast"