arch: include linux/cpu.h for trap_init() prototype

some architectures run into a -Wmissing-prototypes warning
for trap_init()

arch/microblaze/kernel/traps.c:21:6: warning: no previous prototype for 'trap_init' [-Wmissing-prototypes]

Include the right header to avoid this consistently, removing
the extra declarations on m68k and x86 that were added as local
workarounds already.

Signed-off-by: Arnd Bergmann <[e-mail]>

arch/alpha/kernel/traps.c

···
  * This file initializes the trap entry points
  */
 
+#include <linux/cpu.h>
 #include <linux/jiffies.h>
 #include <linux/mm.h>
 #include <linux/sched/signal.h>

arch/csky/include/asm/traps.h

···
 asmlinkage void do_notify_resume(struct pt_regs *regs,
 			unsigned long thread_info_flags);
 
-void trap_init(void);
-
 #endif /* __ASM_CSKY_TRAPS_H */

arch/csky/kernel/traps.c

···
 // SPDX-License-Identifier: GPL-2.0
 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
 
+#include <linux/cpu.h>
 #include <linux/sched.h>
 #include <linux/signal.h>
 #include <linux/kernel.h>

arch/m68k/coldfire/vectors.c

···
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/irq.h>
+#include <linux/cpu.h>
 #include <asm/traps.h>
 #include <asm/machdep.h>
 #include <asm/coldfire.h>
 #include <asm/mcfsim.h>
 #include <asm/mcfwdebug.h>
-
-#include "vectors.h"
 
 /***************************************************************************/
 

arch/m68k/coldfire/vectors.h

···
-/* SPDX-License-Identifier: GPL-2.0-only */
-
-void trap_init(void);

arch/microblaze/kernel/traps.c

···
  * for more details.
  */
 
+#include <linux/cpu.h>
 #include <linux/export.h>
 #include <linux/kernel.h>
 #include <linux/kallsyms.h>

arch/sparc/kernel/traps_32.c

···
  * I hate traps on the sparc, grrr...
  */
 
+#include <linux/cpu.h>
 #include <linux/sched/mm.h>
 #include <linux/sched/debug.h>
 #include <linux/mm_types.h>

arch/sparc/kernel/traps_64.c

···
  * I like traps on v9, :))))
  */
 
+#include <linux/cpu.h>
 #include <linux/extable.h>
 #include <linux/sched/mm.h>
 #include <linux/sched/debug.h>

arch/x86/include/asm/traps.h

···
 asmlinkage __visible notrace struct pt_regs *sync_regs(struct pt_regs *eregs);
 asmlinkage __visible notrace
 struct pt_regs *fixup_bad_iret(struct pt_regs *bad_regs);
-void __init trap_init(void);
 asmlinkage __visible noinstr struct pt_regs *vc_switch_off_ist(struct pt_regs *eregs);
 #endif
 

arch/x86/kernel/traps.c

···
 #include <linux/nmi.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
+#include <linux/cpu.h>
 #include <linux/io.h>
 #include <linux/hardirq.h>
 #include <linux/atomic.h>