64-bit counters that wrap on overflow. They are collecte once per
second from the chips. Currently they can be retrieved via a sysctl phy_stats.
A write of an arbitrary value to the sysctl atomically retrieves the
statistics and clears them.
It currently supports the PMC Sierra Lite, Ultra and 622 chips and
the IDT 77105. The driver handles media options and state in a consistent
manner for ATM drivers. The next commit to the midway driver will make
it use utopia.
