[MIPS] IP27: startup_bridge_irq: connect interrupt.

shutdown_bridge_irq disconnects the irq so we need to connect the irq or
requesting the same irq a send time will fail.  This used to make
things like ifconfig eth0 down; ifconfig eth0 up fail on IP27.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/sgi-ip27/ip27-irq.c

@@ -285,6 +285,8 @@ static unsigned int startup_bridge_irq(unsigned int irq)
 
         bridge->b_wid_tflush;
 
+	intr_connect_level(cpu, swlevel);
+
         return 0;       /* Never anything pending.  */
 }