Revert "disable key"

This reverts commit 1a25a15695.

sw_usb_audio/app_usb_aud_phaten_golden/src/extensions/dsp.c

@@ -67,7 +67,7 @@ void key_receiver(chanend_t c)
     // tile0
     // load the license key
     // This function must be called before audio_ex3d_activate_key.
-  //  audio_ex3d_load_key(c);
+    audio_ex3d_load_key(c);
 }
 
 void key_sender(chanend_t c)
@@ -77,14 +77,12 @@ void key_sender(chanend_t c)
     // tile1
     // activate the license key
     // if the keys match, the function returns 0.
-#if 0
     int ret = audio_ex3d_activate_key(c);
     if (ret == NO_ERR) {
         debug_printf("License keys match.\n");
     } else {
         debug_printf("License keys do not match. Error code: %d\n", ret);
     }
-#endif
 }
 
 void UserBufferManagementInit(unsigned sampFreq)