ARM: at91: sparse irq support

Enable sparse irq support for multisoc image. It involves to add the
NR_IRQS_LEGACY offset to static SoC irq number definitions since NR_IRQS_LEGACY
irq descs are allocated before AIC requests irq descs allocation.
Move NR_AIC_IRQS macro to a more appropiate place with the purpose to
remove mach/irqs.h later.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
diff --git a/arch/arm/mach-at91/at91sam9261.c b/arch/arm/mach-at91/at91sam9261.c
index c77d503..f40762c 100644
--- a/arch/arm/mach-at91/at91sam9261.c
+++ b/arch/arm/mach-at91/at91sam9261.c
@@ -19,6 +19,7 @@
 #include <asm/system_misc.h>
 #include <mach/cpu.h>
 #include <mach/at91sam9261.h>
+#include <mach/at91_aic.h>
 #include <mach/at91_pmc.h>
 #include <mach/at91_rstc.h>