if_ate handles the bytes of the MAC address in a "wrong" order

[M. Warner Losh]

I think these patches are basically good.  I gotta think about how I
wanna roll these into the kernel as I have units in the field that
upgrading their boot loader would be awkward...

Why do you look at all four SA registers, but only pick the first
non-zero one?  Why is that going to he better than just looking at the
first one?  Until FreeBSD can support muliple MAC addresses, I'm not
sure I see the point...

Warner