arge1 still works (it's the standalone PHY) but arge0 and the other switch
ports don't work. They're enumerated though, demonstrating that the
mdiobus abstraction is correctly working.
This uses the new firmware(9) method for squirreling away the EEPROM
contents from SPI flash so ath(4) can get to them later.
It won't work out of the box just yet - you have to add this to
if_ath_pci.c:
#define ATH_EEPROM_FIRMWARE
.. until I've added it as a configuration option and updated things.
