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

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

arch/xtensa/mm/fault.c:87:6: warning: no previous prototype for 'do_page_fault' [-Wmissing-prototypes]
87 | void do_page_fault(struct pt_regs *regs)

Signed-off-by: Randy Dunlap <[e-mail]>
Cc: Chris Zankel <[e-mail]>
Cc: Max Filippov <[e-mail]>
Message-Id: <[e-mail]>
Signed-off-by: Max Filippov <[e-mail]>

arch/xtensa/mm/fault.c

···
 #include <asm/mmu_context.h>
 #include <asm/cacheflush.h>
 #include <asm/hardirq.h>
+#include <asm/traps.h>
 
 void bad_page_fault(struct pt_regs*, unsigned long, int);