qed: Fix non TCP packets should be dropped on iWARP ll2 connection

FW workaround. The iWARP LL2 connection did not expect TCP packets
to arrive on it's connection. The fix drops any non-tcp packets

Fixes b5c29ca7 ("qed: iWARP CM - setup a ll2 connection for handling
SYN packets")

Signed-off-by: Michal Kalderon <Michal.Kalderon@cavium.com>
Signed-off-by: Ariel Elior <Ariel.Elior@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>