uses one or the other. This required some changes to the ahc_reset()
function, and how early the probes had to allocate their softc.
Turn the AHC_IN/OUT* macros into inline functions and lowercase their names
to indicate this change. Geting AHC_OUTSB to work as a macro doing
conditional memory mapped I/O would have been too gross.
Be smart about the STPWEN control bit in SCFRCTL1. It should only be set
if the low byte of the bus is to be terminated. We figure this out either
by "caching" the value left over from the BIOS setup before we reset the card
or by using the values stored in the seeprom if it is availible.