ARM: at91: fix at91x40 build

patch 738a0fd "ARM: at91: fix external interrupts in non-DT case"
fixed a run-time error on some at91 platforms but did not apply
the same change to at91x40, which now doesn't build.

This changes at91x40 in the same way that the other platforms
were changed.

Signed-off-by: Arnd Bergmann <[email protected]>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <[email protected]>

arch/arm/mach-at91/at91x40.c

@@ -88,6 +88,6 @@ void __init at91x40_init_interrupts(unsigned int priority[NR_AIC_IRQS])
 	if (!priority)
 		priority = at91x40_default_irq_priority;
 
-	at91_aic_init(priority);
+	at91_aic_init(priority, at91_extern_irq);
 }