. Make internal service routines static.
. Use a consistent ordering of checks in MII_TICK. Do the work in the
mii_phy_tick() subroutine if appropriate.
. Call mii_phy_update() to trigger the callbacks.
Parag Patel did all of the grunt work, so he gets the credit.
Register definitions and actions inferred from a Linux driver,
so Intel also gets some 'credit'.