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/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 3279646..5fb1064 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -40,6 +40,7 @@
 	select ARCH_THREAD_INFO_ALLOCATOR
 	select ARCH_CLOCKSOURCE_DATA
 	select GENERIC_TIME_VSYSCALL_OLD
+	select SYSCTL_ARCH_UNALIGN_NO_WARN
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_RELA
 	default y