xtensa: irq: include <asm/traps.h>

Use <asm/traps.h> to provide the function prototype for do_IRQ()
to prevent a build warning:

arch/xtensa/kernel/irq.c:34:17: warning: no previous prototype for 'do_IRQ' [-Wmissing-prototypes]
   34 | asmlinkage void do_IRQ(int hwirq, struct pt_regs *regs)

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Message-Id: <20230920052139.10570-4-rdunlap@infradead.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>