power: Release interaction lock when idle state is detected

An idle state node has been added to some of our common kernels
(e.g. qcom_msm8998). Use this node to unlock interaction boost before
the timeout expires when screen updates are not expected soon.

Change-Id: I43d1e2f2cbd6713baa132be7eb475243a8d4a5c6

power-common.h

@@ -45,6 +45,13 @@ extern "C" {
 
 enum CPU_GOV_CHECK { CPU0 = 0, CPU1 = 1, CPU2 = 2, CPU3 = 3 };
 
+enum INTERACTION_STATE {
+    INTERACTION_STATE_UNINITIALIZED,
+    INTERACTION_STATE_IDLE,
+    INTERACTION_STATE_INTERACTION,
+    INTERACTION_STATE_WAITING,
+};
+
 void power_init(void);
 void power_hint(power_hint_t hint, void* data);
 bool is_expensive_rendering_supported();