- fixed prj.conf for ISO support

- Allow for manual disabling SD sync
- add uart0 define to board dt overlay
- tested and working ISO support over USB-CDC Segger VUART0/1 and external UART

src/audio_sync_timer_rtc.c

@@ -9,7 +9,6 @@
 #include <zephyr/kernel.h>
 #include <zephyr/init.h>
 #include <nrfx_dppi.h>
-#include <nrfx_i2s.h>
 #include <nrfx_ipc.h>
 #include <nrfx_rtc.h>
 #include <nrfx_timer.h>

src/main.c

@@ -470,6 +470,7 @@ int main(void)
 		uart_irq_tx_enable(hci_uart_dev);
 		k_sleep( K_MSEC(100) );
 	}
+    return 0;
 #endif
 
     while (1) {