[PATCH] powerpc/stacktrace: Include linux/delay.h

commit 7c6986ade69e ("powerpc/stacktrace: Fix spurious "stale" traces in raise_backtrace_ipi()")
introduces udelay() call without including the linux/delay.h header.
This may happen to work on master but the header that declares the
functionshould be included nonetheless.

Fixes: 7c6986ade69e ("powerpc/stacktrace: Fix spurious "stale" traces in raise_backtrace_ipi()")
Signed-off-by: Michal Suchanek <redacted>
---
V2: Add header in alphabetical order.
---
 arch/powerpc/kernel/stacktrace.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c
index 2b0d04a1b7d2..9e4a4a7af380 100644
--- a/arch/powerpc/kernel/stacktrace.c
+++ b/arch/powerpc/kernel/stacktrace.c

@@ -8,6 +8,7 @@
  * Copyright 2018 Nick Piggin, Michael Ellerman, IBM Corp.
  */
 
+#include <linux/delay.h>
 #include <linux/export.h>
 #include <linux/kallsyms.h>
 #include <linux/module.h>

-- 
2.26.2