Improve watch_tcc to decouple leds and buzzer as much as allowed

As a positive side effect, the led will stop emitting the faintiest
of blinks when the buzzer starts playing.

watch-library/simulator/watch/watch.c

@@ -1,9 +1,5 @@
 #include "watch.h"
 
-bool watch_is_buzzer_or_led_enabled(void) {
-    return false;
-}
-
 bool watch_is_usb_enabled(void) {
     return true;
 }

watch-library/simulator/watch/watch_private.c

@@ -51,8 +51,6 @@ int _gettimeofday(struct timeval *tv, void *tzvp) {
     return 0;
 }
 
-void _watch_disable_tcc(void) {}
-
 void _watch_enable_usb(void) {}
 
 void watch_disable_TRNG() {}

watch-library/simulator/watch/watch_tcc.c

@@ -46,8 +46,6 @@ static watch_cb_t _cb_start_global = NULL;
 static watch_cb_t _cb_stop_global = NULL;
 static volatile bool _buzzer_is_active = false;
 
-void _watch_enable_tcc(void) {}
-
 static inline void _em_interval_stop() {
     emscripten_clear_interval(_em_interval_id);
     _em_interval_id = 0;