Also remove dispatchers from wakeup when killing

kernel/arch/armv8/syscall.c

@@ -33,6 +33,7 @@
 #include <arch/arm/platform.h>
 #include <arch/arm/syscall_arm.h>
 #include <serial.h>
+#include <wakeup.h>
 
 // helper macros  for invocation handler definitions
 #define INVOCATION_HANDLER(func) \
@@ -91,7 +92,9 @@ handle_dispatcher_stop(
 {
     assert(argc == 2);
 
+    // TODO rueegges: kill using capability deletion once it is ready for last delete?
     scheduler_remove(to->u.dispatcher.dcb);
+    wakeup_remove(to->u.dispatcher.dcb);
 
     return SYSRET(SYS_ERR_OK);
 }