gateworks/avila board support

[Sam Leffler]

I'm working to fill in the missing bits for gateworks/avila boards.  I 
just fixed usb and am working on the 4-port switch, ixp425 crypto 
support, and anything else I hit.  I'm aware of one issue where stuffing 
all 4 mini-pci slots in a 2348-4 board results in unreliable interrupts.

If you are aware of any other problems please let me know or better yet 
file a PR and assign it to me.  Can't promise I can fix 'em this time 
'round but will try.

    Sam