[Audio] Add support for audio shutdown pin (#22731)

Co-authored-by: Ryan <fauxpark@gmail.com>

platforms/test/drivers/audio_pwm_hardware.c

@@ -15,6 +15,6 @@
 
 #include "audio.h"
 
-void audio_driver_initialize(void) {}
-void audio_driver_start() {}
-void audio_driver_stop() {}
+void audio_driver_initialize_impl(void) {}
+void audio_driver_start_impl() {}
+void audio_driver_stop_impl() {}