Force alphas to prefer mem mapping as the default.
Basically, we have a pointer to a function which we can call which will
return us a pointer to firmware for the card we have. We call this function
(if it's non-NULL) with the address of our mdvec f/w pointer.
The way this works is that if ispfw (as a module or a static) is loaded,
it initializes the pointer in isp_pci, so we can call into to it to fetch
a pointer to a f/w set.
If ispfw is MOD_UNLOADed, it's retained a pointer to our mdvec f/w pointers,
which then get zeroed out so we don't have any references to data that's
now gone from kernel memory. Removing the f/w saves ~360KBytes.
Alas, there is no autounload mechanism that works for is here.