A couple of drivers and one place in if.c use ETH_ADDR_LEN, even though
net/ethernet.h provides an equivalent ETHER_ADDR_LEN definition.
Cleanup all of the locations which refer to ETH_ADDR_LEN to use the
standard ETHER_ADDR_LEN instead.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>