msm: pm2: Add cores hotplug callback function

Add the hotplug callback function in pm2 driver to
avoid the single binary compilaton issues.

Change-Id: I3d79904c1b266e87f7ac0707400a8aac44529f0f
Signed-off-by: Murali Nalajala <mnalajal@codeaurora.org>
diff --git a/arch/arm/mach-msm/pm2.c b/arch/arm/mach-msm/pm2.c
index e1934bb..7977d22 100644
--- a/arch/arm/mach-msm/pm2.c
+++ b/arch/arm/mach-msm/pm2.c
@@ -1668,6 +1668,13 @@
 	.valid = suspend_valid_only_mem,
 };
 
+/* Hotplug the "non boot" CPU's and put
+ * the cores into low power mode
+ */
+void msm_pm_cpu_enter_lowpower(unsigned int cpu)
+{
+	return;
+}
 
 /******************************************************************************
  * Restart Definitions