Replace bcopy() to update ether_addr

[Adrian Chadd]

You can't assume the ethernet addresses will be aligned.

For wifi headers you're definitely going to have at least one address
be non-dword aligned, even if the header itself is dword aligned.

The whole point of using a macro is so it becomes really easy to
change the copy type at compile time. Otherwise I'll have to go
through the code, find all the (CPU intensive/stalling) places where
those 6 byte copies are occuring and replace them.



Adrian