added initial support of mousekeys to ps2_vusb

ps2_vusb/mousekey.h

@@ -0,0 +1,12 @@
+#ifndef MOUSEKEY_H
+#define  MOUSEKEY_H
+
+#include <stdbool.h>
+#include "host.h"
+
+void mousekey_decode(uint8_t code);
+bool mousekey_changed(void);
+void mousekey_send(void);
+void mousekey_clear_report(void);
+
+#endif