tests: bluetooth: shell: use generic CDC ACM shield

Remove CDC ACM UART devicetree and config overlay, and explicit
USB support initialization in favor of generic CDC ACM shield.
For shell support via USB CDC ACM, this example is to be built
as follows:

west build -b nrf52840dongle_nrf52840
  tests/bluetooth/shell -- -DSHIELD=cdc_acm_shell

Signed-off-by: Johann Fischer <[email protected]>

Author: jfischer-no

tests/bluetooth/shell/cdc_acm.conf

@@ -123,21 +123,6 @@ static void hrs_notify(void)
 
 void main(void)
 {
-#if DT_NODE_HAS_COMPAT(DT_CHOSEN(zephyr_shell_uart), zephyr_cdc_acm_uart)
-	const struct device *dev;
-	uint32_t dtr = 0;
-
-	dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_shell_uart));
-	if (!device_is_ready(dev) || usb_enable(NULL)) {
-		return;
-	}
-
-	while (!dtr) {
-		uart_line_ctrl_get(dev, UART_LINE_CTRL_DTR, &dtr);
-		k_sleep(K_MSEC(100));
-	}
-#endif
-
 	printk("Type \"help\" for supported commands.");
 	printk("Before any Bluetooth commands you must `bt init` to initialize"
 	       " the stack.\n");

tests/bluetooth/shell/src/main.c

@@ -8,8 +8,7 @@ tests:
     harness: keyboard
     min_flash: 145
   bluetooth.shell.cdc_acm:
-    extra_args: OVERLAY_CONFIG=cdc_acm.conf
-                DTC_OVERLAY_FILE="usb.overlay"
+    extra_args: SHIELD="cdc_acm_shell"
     depends_on: usb_device
     platform_allow: native_posix native_posix_64 nrf52840dk_nrf52840
     platform_exclude: nrf52dk_nrf52810