m68k: Add missing types to asm/irq.h

As reported in commit f8b648bf6628 ("net: sunhme: move asm includes to
below linux includes") when including this <asm/*> header before the
needed <linux/*> headers the compilation will fail because of missing
types:

arch/m68k/include/asm/irq.h:66:20: warning: ‘struct pt_regs’ declared inside parameter list will not be visible outside of this definition or declaration
66 | struct pt_regs *));
| ^~~~~~~
arch/m68k/include/asm/irq.h:78:11: error: expected ‘;’ before ‘void’
78 | asmlinkage void do_IRQ(int irq, struct pt_regs *regs);
| ^~~~~
| ;
arch/m68k/include/asm/irq.h:78:40: warning: ‘struct pt_regs’ declared inside parameter list will not be visible outside of this definition or declaration
78 | asmlinkage void do_IRQ(int irq, struct pt_regs *regs);
| ^~~~~~~
arch/m68k/include/asm/irq.h:79:8: error: unknown type name ‘atomic_t’
79 | extern atomic_t irq_err_count;
| ^~~~~~~~

Signed-off-by: Rolf Eike Beer <[e-mail]>
Reviewed-by: Geert Uytterhoeven <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Geert Uytterhoeven <[e-mail]>

arch/m68k/include/asm/irq.h

···
 #ifndef _M68K_IRQ_H_
 #define _M68K_IRQ_H_
 
+#include <linux/atomic.h>
+#include <linux/linkage.h>
+
 /*
  * This should be the same as the max(NUM_X_SOURCES) for all the
  * different m68k hosts compiled into the kernel.
···
 struct irq_data;
 struct irq_chip;
 struct irq_desc;
+struct pt_regs;
+
 extern unsigned int m68k_irq_startup(struct irq_data *data);
 extern unsigned int m68k_irq_startup_irq(unsigned int irq);
 extern void m68k_irq_shutdown(struct irq_data *data);