rocker: silence shift wrapping warning

"val" is declared as a u64 so static checkers complain that this shift
can wrap.  I don't have the hardware but probably it's doesn't have over
31 ports.  Still we may as well silence the warning even if it's not a
real bug.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/rocker/rocker.c

@@ -1257,9 +1257,9 @@ static void rocker_port_set_enable(struct rocker_port *rocker_port, bool enable)
 	u64 val = rocker_read64(rocker_port->rocker, PORT_PHYS_ENABLE);
 
 	if (enable)
-		val |= 1 << rocker_port->lport;
+		val |= 1ULL << rocker_port->lport;
 	else
-		val &= ~(1 << rocker_port->lport);
+		val &= ~(1ULL << rocker_port->lport);
 	rocker_write64(rocker_port->rocker, PORT_PHYS_ENABLE, val);
 }