cpuidle/pseries: Fix fallout caused due to cleanup in pseries cpuidle backend driver

Commit d8c6ad31 ("sched/idle, PPC: Remove redundant
cpuidle_idle_call()") reintroduced ppc64_runlatch_off/on() in the
pseries cpuidle backend driver. Hence the cleanup caused by the
commit "c0c4301c:pseries/cpuidle: Remove redundant call
to ppc64_runlatch_off() in cpu idle routines"  in conjuction
with the commit d8c6ad31 causes a build failure.
Signed-off-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: http://lkml.kernel.org/r/52FAFD2D.2090306@linux.vnet.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

drivers/cpuidle/cpuidle-pseries.c

@@ -17,6 +17,7 @@
 #include <asm/reg.h>
 #include <asm/machdep.h>
 #include <asm/firmware.h>
+#include <asm/runlatch.h>
 #include <asm/plpar_wrappers.h>
 
 struct cpuidle_driver pseries_idle_driver = {