usb: chipidea: debug: add runtime pm for register access

Add runtime pm operations for registers access to avoid system hang.

Signed-off-by: Li Jun <[e-mail]>

drivers/usb/chipidea/debug.c

···
 	unsigned long flags;
 	unsigned mode;
 
+	pm_runtime_get_sync(ci->dev);
 	spin_lock_irqsave(&ci->lock, flags);
 	mode = hw_port_test_get(ci);
 	spin_unlock_irqrestore(&ci->lock, flags);
+	pm_runtime_put_sync(ci->dev);
 
 	seq_printf(s, "mode = %u\n", mode);
 
···
 	if (sscanf(buf, "%u", &mode) != 1)
 		return -EINVAL;
 
+	pm_runtime_get_sync(ci->dev);
 	spin_lock_irqsave(&ci->lock, flags);
 	ret = hw_port_test_set(ci, mode);
 	spin_unlock_irqrestore(&ci->lock, flags);
+	pm_runtime_put_sync(ci->dev);
 
 	return ret ? ret : count;
 }
···
 	if (role == CI_ROLE_END || role == ci->role)
 		return -EINVAL;
 
+	pm_runtime_get_sync(ci->dev);
 	ci_role_stop(ci);
 	ret = ci_role_start(ci, role);
+	pm_runtime_put_sync(ci->dev);
 
 	return ret ? ret : count;
 }