ixgbe patch to provide NIC's tx/rx counters via ethtool

When LRO is enabled, the received packet and byte counters represent the
LRO'd packets, not the packets/bytes on the wire.  The Intel 82599 NIC has
registers that keep count of the physical packets.  Add these counters to
the ethtool stats.  The byte counters are 36-bit, but the high 4 bits were
being ignored in the 2.6.31 ixgbe driver:  Read those as well to allow
longer time between polling the stats to detect wraps.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Acked-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>