cdc_acm: turn on UART_TX LED when sending break signals

Software typically asserts line break for an extended period
(e.g. PuTTY will assert continuously until the next keypress), so
provide feedback via the LED.

Also declare variables used in both tinyusb callback and uart_thread context
as volatile.

src/cdc_uart.c

@@ -146,9 +146,7 @@ bool cdc_task(void)
         if (((int)break_expiry - (int)xTaskGetTickCount()) < 0) {
           timed_break = false;
           uart_set_break(PROBE_UART_INTERFACE, false);
-#ifdef PROBE_UART_TX_LED
           tx_led_debounce = 0;
-#endif
         } else {
           keep_alive = true;
         }
@@ -158,9 +156,7 @@ bool cdc_task(void)
       uart_set_break(PROBE_UART_INTERFACE, false);
       timed_break = false;
       was_connected = 0;
-#ifdef PROBE_UART_TX_LED
       tx_led_debounce = 0;
-#endif
       cdc_tx_oe = 0;
     }
     return keep_alive;
@@ -282,19 +278,15 @@ void tud_cdc_send_break_cb(uint8_t itf, uint16_t wValue) {
     case 0xffff:
     uart_set_break(PROBE_UART_INTERFACE, true);
     timed_break = false;
-#ifdef PROBE_UART_TX_LED
     gpio_put(PROBE_UART_TX_LED, 1);
     tx_led_debounce = 1 << 30;
-#endif
     break;
     default:
     uart_set_break(PROBE_UART_INTERFACE, true);
     timed_break = true;
-#ifdef PROBE_UART_TX_LED
     gpio_put(PROBE_UART_TX_LED, 1);
-    tx_led_debounce = 1 << 30;
-#endif
     break_expiry = xTaskGetTickCount() + (wValue * (configTICK_RATE_HZ / 1000));
+    tx_led_debounce = 1 << 30;
     break;
   }
 }

src/usb_descriptors.c

@@ -48,7 +48,7 @@ tusb_desc_device_t const desc_device =
 
     .idVendor           = 0x2E8A, // Pi
     .idProduct          = 0x000c, // CMSIS-DAP Debug Probe
-    .bcdDevice          = 0x0200, // Version 02.00
+    .bcdDevice          = 0x0103, // Version 01.03
     .iManufacturer      = 0x01,
     .iProduct           = 0x02,
     .iSerialNumber      = 0x03,