bnx2x: Show port statistics in Multi-function

Today, port statistics are being presented when using `ethool -S' only
for single-function devices, but there are some port statistics which are
crucial for analyzing bottle-necks. E.g., HW Rx discards due to lack of
buffer space [when device isn't handling ingress traffic fast enough].

Judging the pros and cons, it was decided that in-order to better support
automatic dump-gathering tools, bnx2x should no longer hide those stats.
This leaves only VFs lacking the port statistics.

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