be2net: Clear any capability flags that driver is not interested in.

It is possible for some versions of firmware to advertise capabilities that driver
is not ready to handle. This may lead to controller stall. Since the driver is
interested only in subset of flags, clearing the rest.

Signed-off-by: Sarveshwar Bandi <sarveshwar.bandi@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>