Use Kaleidoscope.useLoopHook() instead of loop_hook_use()

We are trying to migrate to the former, so while I'm here, do so in this plugin,
so we can deprecate and remove `loop_hook_use` sooner.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>

src/Kaleidoscope/LED-ActiveModColor.cpp

@@ -30,7 +30,7 @@ ActiveModColorEffect::ActiveModColorEffect(void) {
 }
 
 void ActiveModColorEffect::begin(void) {
-  loop_hook_use(loopHook);
+  Kaleidoscope.useLoopHook(loopHook);
 }
 
 bool ActiveModColorEffect::isModifierActive(Key key) {