lib_*/board.c: do not initialize bi_enet*addr in global data

lib_*/board.c: do not initialize bi_enet*addr in global data

Since everyone is using the environment for mac address storage, there is
no point in seeding the global data.

The arches that are converted here:
	i386
	m68k
	microblaze
	mips
	nios
	nios2
	sh
	sparc

Signed-off-by: Mike Frysinger <[email protected]>
CC: Ben Warren <[email protected]>
CC: Daniel Hellstrom <[email protected]>
CC: Michal Simek <[email protected]>
CC: Shinya Kuribayashi <[email protected]>
CC: Scott McNutt <[email protected]>
CC: Nobuhiro Iwamatsu <[email protected]>