sparse irqs: handle !GENIRQ platforms

Impact: build fix

fix:

 In file included from /home/mingo/tip/arch/m68k/amiga/amiints.c:39:
 /home/mingo/tip/include/linux/interrupt.h:21: error: expected identifier or '('
 /home/mingo/tip/arch/m68k/amiga/amiints.c: In function 'amiga_init_IRQ':
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/linux/interrupt.h

@@ -14,12 +14,12 @@
 #include <linux/irqflags.h>
 #include <linux/smp.h>
 #include <linux/percpu.h>
+#include <linux/irqnr.h>
+
 #include <asm/atomic.h>
 #include <asm/ptrace.h>
 #include <asm/system.h>
 
-extern int nr_irqs;
-
 /*
  * These correspond to the IORESOURCE_IRQ_* defines in
  * linux/ioport.h to select the interrupt line behaviour.  When

include/linux/irqnr.h

 #ifndef _LINUX_IRQNR_H
 #define _LINUX_IRQNR_H
 
+/*
+ * Generic irq_desc iterators:
+ */
+#ifdef __KERNEL__
+
 #ifndef CONFIG_GENERIC_HARDIRQS
 #include <asm/irq.h>
 # define nr_irqs		NR_IRQS
@@ -11,10 +16,12 @@
 # define for_each_irq_desc_reverse(irq, desc)                          \
 	for (irq = nr_irqs - 1; irq >= 0; irq--)
 #else
+
+extern int nr_irqs;
+
 #ifndef CONFIG_SPARSE_IRQ
 
 struct irq_desc;
-extern int nr_irqs;
 # define for_each_irq_desc(irq, desc)		\
 	for (irq = 0, desc = irq_desc; irq < nr_irqs; irq++, desc++)
 # define for_each_irq_desc_reverse(irq, desc)                          \
@@ -26,4 +33,6 @@ extern int nr_irqs;
 #define for_each_irq_nr(irq)                   \
        for (irq = 0; irq < nr_irqs; irq++)
 
+#endif /* __KERNEL__ */
+
 #endif

include/linux/random.h

@@ -8,6 +8,7 @@
 #define _LINUX_RANDOM_H
 
 #include <linux/ioctl.h>
+#include <linux/irqnr.h>
 
 /* ioctl()'s for the random number generator */
 
@@ -49,7 +50,6 @@ struct timer_rand_state;
 
 extern struct timer_rand_state *irq_timer_state[];
 
-extern int nr_irqs;
 static inline struct timer_rand_state *get_timer_rand_state(unsigned int irq)
 {
 	if (irq >= nr_irqs)