(drivers) lan91c111: Add I/O-related macros
(drivers) lan91c111: Add I/O-related macros

Add offsets for banks, add macros for 16-bit register store and load,
add function for bank select

embox/embox,embox/embox,Kakadu/embox,embox/embox,Kakadu/embox,Kakadu/embox,Kakadu/embox,Kakadu/embox,Kakadu/embox,embox/embox,embox/embox,Kakadu/embox,embox/embox