powerpc/cpuidle: Handle power_save=off

This patch makes pseries_idle_driver not to be registered when
power_save=off kernel boot option is specified. The
cpuidle_disable variable used here is similar to
its usage on x86. If cpuidle_disable is set then
sysfs entries for cpuidle framework are not created
and the required drivers are not loaded.

Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Trinabh Gupta <g.trinabh@gmail.com>
Signed-off-by: Arun R Bharadwaj <arun.r.bharadwaj@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 811b7e7..b585bff 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -382,6 +382,7 @@
 }
 #endif
 
+extern unsigned long cpuidle_disable;
 enum idle_boot_override {IDLE_NO_OVERRIDE = 0, IDLE_POWERSAVE_OFF};
 
 #endif /* __KERNEL__ */