input: move do_mouse_set to new core

This removes the last user of the lecagy input mouse handler list,
so we can remove more legacy bits with this.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
diff --git a/ui/input.c b/ui/input.c
index 162e8d8..2761911 100644
--- a/ui/input.c
+++ b/ui/input.c
@@ -334,3 +334,24 @@
 
     return mice_list;
 }
+
+void do_mouse_set(Monitor *mon, const QDict *qdict)
+{
+    QemuInputHandlerState *s;
+    int index = qdict_get_int(qdict, "index");
+    int found = 0;
+
+    QTAILQ_FOREACH(s, &handlers, node) {
+        if (s->id == index) {
+            found = 1;
+            qemu_input_handler_activate(s);
+            break;
+        }
+    }
+
+    if (!found) {
+        monitor_printf(mon, "Mouse at given index not found\n");
+    }
+
+    qemu_input_check_mode_change();
+}