tests: Bluetooth: BAP: Fix test wrt stream args to broadcast_source

Due to adding subgroup count and streams per subgroup
arguments to the broadcast_source test, fix the sink
test that was not ported due to being merged for change
in a different PR.

Relates to commit 01e8d0e ("tests: Bluetooth: BAP:
Add subgroup and stream args to broadcast_source").

Fixes commit 303d0b7 ("tests: Bluetooth: BAP: Add
test to test invalid bcode").

Signed-off-by: Vinayak Kariappa Chettimada <vich@nordicsemi.no>

tests/bsim/bluetooth/audio/src/bap_broadcast_sink_test.c

@@ -1088,8 +1088,8 @@ static void test_sink_encrypted_incorrect_code(void)
 	test_broadcast_sync(BROADCAST_CODE);
 
 	/* Wait for all to be started */
-	printk("Waiting for streams to be started\n");
-	for (size_t i = 0U; i < ARRAY_SIZE(streams); i++) {
+	printk("Waiting for %zu streams to be started\n", stream_sync_cnt);
+	for (size_t i = 0U; i < stream_sync_cnt; i++) {
 		k_sem_take(&sem_stream_started, K_FOREVER);
 	}