cpuidle: build fix for non-x86

The last posted version of this patch gave compile error
on IA64. So, here goes yet another rewrite of the patch.

Convert cpu_idle_wait() to cpuidle_kick_cpus() which is
SMP-only, and gives error on non supported CPU.

Changes from last patch sent by Kevin:
Moved the definition of kick_cpus back to cpuidle.c from cpuidle.h:
* Having it in .h gives #error on archs which includes the header file without
  actually having CPU_IDLE configured. To make it work in .h, we need one more
  #ifdef around that code which makes it messy.
* Also, the function is only called from one file. So, it can be in declared
  statically in .c rather than making it available to everyone who includes
  the .h file.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Len Brown <len.brown@intel.com>

arch/x86/Kconfig

@@ -102,6 +102,9 @@ config ARCH_HAS_ILOG2_U32
 config ARCH_HAS_ILOG2_U64
 	def_bool n
 
+config ARCH_HAS_CPU_IDLE_WAIT
+	def_bool y
+
 config GENERIC_CALIBRATE_DELAY
 	def_bool y
 

drivers/cpuidle/cpuidle.c

@@ -27,6 +27,17 @@ static void (*pm_idle_old)(void);
 
 static int enabled_devices;
 
+#if defined(CONFIG_ARCH_HAS_CPU_IDLE_WAIT)
+static void cpuidle_kick_cpus(void)
+{
+	cpu_idle_wait();
+}
+#elif defined(CONFIG_SMP)
+# error "Arch needs cpu_idle_wait() equivalent here"
+#else /* !CONFIG_ARCH_HAS_CPU_IDLE_WAIT && !CONFIG_SMP */
+static void cpuidle_kick_cpus(void) {}
+#endif
+
 /**
  * cpuidle_idle_call - the main idle loop
  *
@@ -83,7 +94,7 @@ void cpuidle_uninstall_idle_handler(void)
 {
 	if (enabled_devices && (pm_idle != pm_idle_old)) {
 		pm_idle = pm_idle_old;
-		cpu_idle_wait();
+		cpuidle_kick_cpus();
 	}
 }