eHEA: Fix bonding support

The driver didn't allow an interface's MAC address to be modified if the
respective interface wasn't setup - a failing Hcall was the result. Thus
bonding wasn't usable. The fix moves the failing Hcall which was registering
a MAC address for the reception of BC packets in firmware from the port up
and down functions to the port resources setup functions. Additionally the
missing update of the last_rx member of the netdev structure was added.

Signed-off-by: Thomas Klein <tklein@de.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>