bnx2x: Don't show port statistics for VFs

VFs are currently showing port statistics, although they can't really access
those - thus all such statistics will always show a value of 0.

This patch removes said statistics from the VF's view as to not confuse the
user.

Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: Ariel Elior <Ariel.Elior@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>