xkb: fill in keycode and event type for slow keys enablement

eventType is set for the type that triggered a XkbControlsNotify event.
Technically, SlowKeys is triggered by a timer which doesn't have a matching
core event type. So we used to use 0 here.

Practically, the timer is triggered by a key press + hold and cancelled when
the key is released before the timeout expires. So we might as well set
KeyPress (keycode) in the ControlsNotify to give clients a chance to differ
between timer-triggered SlowKeys and client-triggered ones.

This is a chance in behaviour, though I suspect with little impact.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Acked-by: Daniel Stone <daniel@fooishbar.org>

include/xkbsrv.h

@@ -171,6 +171,7 @@ typedef struct _XkbSrvInfo {
     KeyCode mouseKey;
     KeyCode inactiveKey;
     KeyCode slowKey;
+    KeyCode slowKeyEnableKey;
     KeyCode repeatKey;
     CARD8 krgTimerActive;
     CARD8 beepType;