net: ovs: remove unused hardirq.h

Preempt counter APIs have been split out, currently, hardirq.h just
includes irq_enter/exit APIs which are not used by openvswitch at all.

So, remove the unused hardirq.h.

Signed-off-by: Yang Shi <yang.s@alibaba-inc.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: dev@openvswitch.org
Signed-off-by: David S. Miller <davem@davemloft.net>

net/openvswitch/vport-internal_dev.c

@@ -16,7 +16,6 @@
  * 02110-1301, USA
  */
 
-#include <linux/hardirq.h>
 #include <linux/if_vlan.h>
 #include <linux/kernel.h>
 #include <linux/netdevice.h>