sysctl: Enable IA64 "ignore-unaligned-usertrap" to be used cross-arch

IA64 defines /proc/sys/kernel/ignore-unaligned-usertrap to control
verbose warnings on unaligned access emulation.

Although the exact mechanics of what to do with sysctl (ignore/shout)
are arch specific, this change enables the sysctl to be usable cross-arch.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/init/Kconfig b/init/Kconfig
index 7d30240..523bee1 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1232,6 +1232,13 @@
 	help
 	  Enable support for /proc/sys/debug/exception-trace.
 
+config SYSCTL_ARCH_UNALIGN_NO_WARN
+	bool
+	help
+	  Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
+	  Allows arch to define/use @no_unaligned_warning to possibly warn
+	  about unaligned access emulation going on under the hood.
+
 config KALLSYMS
 	 bool "Load all symbols for debugging/ksymoops" if EXPERT
 	 default y