Change USBSerial.h constructor to allow to label the stream for, eg., redirecting stdin/out/err to a USBSerial object. Will not break existing default use as tested with mbed-os 5.11.5

Dependents:   max32630fthr_stdout2usb_mbed_v5-11-5 firmware_framework1

Revision:
4:eaa07ce86d49
Parent:
1:80ab0d068708
Child:
25:7c72828865f3
--- a/USBAudio/USBAudio.h	Sun Oct 14 12:38:56 2012 +0000
+++ b/USBAudio/USBAudio.h	Sun Oct 14 13:39:27 2012 +0000
@@ -30,6 +30,7 @@
 /**
 * USBAudio example
 *
+* @code
 * #include "mbed.h"
 * #include "USBAudio.h"
 *