Input: add key code for ambient light sensor button

Many notebooks have a special button for enabling/disabling ambient
light sensor.
Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

include/uapi/linux/input.h

@@ -719,6 +719,8 @@ struct input_keymap_entry {
 #define BTN_DPAD_LEFT		0x222
 #define BTN_DPAD_RIGHT		0x223
 
+#define KEY_ALS_TOGGLE		0x230	/* Ambient light sensor */
+
 #define BTN_TRIGGER_HAPPY		0x2c0
 #define BTN_TRIGGER_HAPPY1		0x2c0
 #define BTN_TRIGGER_HAPPY2		0x2c1