Ethernet phy update - 11: added extended phy port register / de-register routines

Added #extended #phy #port #register / #de-register #routine s in ethernet module. This will be the external API to #handle the #hierarchical #processing associated with the phy port register / de-register operations.

#Ethernet update 121 ...
[commit 6db19a2486692753d7fd3f0d8937f56b78cd099f]