Offset for smc91x must be zero otherwise smc91x linux kernel driver does not
detect smc91x ethernet hardware in qemu N900 machine.

The 0x300 offset was used to supress a warning the smsc911x
driver produces about non-standard offset as 0x300 seems to
be the EEPROM default. As only three address lines are
connected both 0 and 0x300 will work just fine with 0 being
correct. The warning about the non-standard offset can be
fixed by writing to EEPROM as that's needed in any case to
set the MAC address.
Signed-off-by: NPali Rohár <pali.rohar@gmail.com>
[tony@atomide.com: updated comments, just use 0 instead of 0x0]
Signed-off-by: NTony Lindgren <tony@atomide.com>