m68knommu: Move forward declaration of do_IRQ() from machdep.h to irq.h

It is not machine-specific, but common irq infrastructure.
Also add the missing asmlinkage, to match its definition.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>

arch/m68k/include/asm/irq.h

@@ -122,4 +122,6 @@ asmlinkage void __m68k_handle_int(unsigned int, struct pt_regs *);
 #define irq_canonicalize(irq)  (irq)
 #endif /* CONFIG_MMU */
 
+asmlinkage void do_IRQ(int irq, struct pt_regs *regs);
+
 #endif /* _M68K_IRQ_H_ */

arch/m68k/include/asm/machdep.h

@@ -40,6 +40,5 @@ extern unsigned long hw_timer_offset(void);
 extern irqreturn_t arch_timer_interrupt(int irq, void *dummy);
 
 extern void config_BSP(char *command, int len);
-extern void do_IRQ(int irq, struct pt_regs *fp);
 
 #endif /* _M68K_MACHDEP_H */