intel_th: Don't touch switch routing in host mode

When the Trace Hub is operating in Host Debugger mode, it is up to the
debugger to configure master routing even for the software sources. Do
not do this in the driver in this case.

Signed-off-by: Alexander Shishkin <[e-mail]>

drivers/hwtracing/intel_th/core.c

···
 	struct intel_th_device *hub = to_intel_th_hub(thdev);
 	struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
 
+	/* In host mode, this is up to the external debugger, do nothing. */
+	if (hub->host_mode)
+		return 0;
+
 	if (!hubdrv->set_output)
 		return -ENOTSUPP;