ARM: psci: add constants to specify affinity levels

This patch defines constants to allow callers of the psci 'suspend'
& 'off' calls specify supported affinity levels.

Signed-off-by: Achin Gupta <achin.gupta@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h
index ce0dbe7..78ce38f 100644
--- a/arch/arm/include/asm/psci.h
+++ b/arch/arm/include/asm/psci.h
@@ -16,6 +16,10 @@
 
 #define PSCI_POWER_STATE_TYPE_STANDBY		0
 #define PSCI_POWER_STATE_TYPE_POWER_DOWN	1
+#define PSCI_POWER_STATE_AFFINITY_LEVEL0	0
+#define PSCI_POWER_STATE_AFFINITY_LEVEL1	1
+#define PSCI_POWER_STATE_AFFINITY_LEVEL2	2
+#define PSCI_POWER_STATE_AFFINITY_LEVEL3	3
 
 struct psci_power_state {
 	u16	id;