power: Adds POWER_HINT_DISABLE_TOUCH

POWER_HINT_DISABLE_TOUCH is used to hint power hal that device is
in a state that touch controller could be disabled to save power.

Bug: 30143923
Change-Id: I56c588e62afadffdb367b6e2c3115cffef51bb45
diff --git a/include/hardware/power.h b/include/hardware/power.h
index f15e3cd..bd8216e 100644
--- a/include/hardware/power.h
+++ b/include/hardware/power.h
@@ -64,7 +64,8 @@
     POWER_HINT_LOW_POWER = 0x00000005,
     POWER_HINT_SUSTAINED_PERFORMANCE = 0x00000006,
     POWER_HINT_VR_MODE = 0x00000007,
-    POWER_HINT_LAUNCH = 0x00000008
+    POWER_HINT_LAUNCH = 0x00000008,
+    POWER_HINT_DISABLE_TOUCH = 0x00000009
 } power_hint_t;
 
 typedef enum {
@@ -248,6 +249,14 @@
      *     device can sustain it. The data parameter is non-zero when the mode
      *     is activated and zero when deactivated.
      *
+     * POWER_HINT_DISABLE_TOUCH
+     *
+     *     When device enters some special modes, e.g. theater mode in Android
+     *     Wear, there is no touch interaction expected between device and user.
+     *     Touch controller could be disabled in those modes to save power.
+     *     The data parameter is non-zero when touch could be disabled, and zero
+     *     when touch needs to be re-enabled.
+     *
      * A particular platform may choose to ignore any hint.
      *
      * availability: version 0.2