bnx2x: Prevent tunnel config for 577xx

Only the 578xx adapters are capable of configuring UDP ports for
the purpose of tunnelling - doing the same on 577xx might lead to
a firmware assertion.
We're already not claiming support for any related feature for such
devices, but we also need to prevent the configuration of the UDP
ports to the device in this case.

Fixes: f34fa14c ("bnx2x: Add vxlan RSS support")
Reported-by: Anikina Anna <anikina@gmail.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>