Input: add KEY_ROTATE_LOCK_TOGGLE

The key has the same use as the SW_ROTATE_LOCK, but is used on devices
where the state is not tracked by the hardware but has to be handled
in software.
Signed-off-by: NStefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: NDarren Hart (VMware) <dvhart@infradead.org>

include/uapi/linux/input-event-codes.h

@@ -594,6 +594,7 @@
 #define BTN_DPAD_RIGHT		0x223
 
 #define KEY_ALS_TOGGLE		0x230	/* Ambient light sensor */
+#define KEY_ROTATE_LOCK_TOGGLE	0x231	/* Display rotation lock */
 
 #define KEY_BUTTONCONFIG		0x240	/* AL Button Configuration */
 #define KEY_TASKMANAGER		0x241	/* AL Task/Project Manager */