bootstd: Keep track of use of usb stop

When 'usb stop' is run, doing 'bootflow scan' does not run the USB hunter
again so does not see any devices. Fix this by telling bootstd about the
state of USB.

Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/usb/host/usb-uclass.c

@@ -9,6 +9,7 @@
 #define LOG_CATEGORY UCLASS_USB
 
 #include <common.h>
+#include <bootdev.h>
 #include <dm.h>
 #include <errno.h>
 #include <log.h>
@@ -208,6 +209,13 @@ int usb_stop(void)
 #ifdef CONFIG_USB_STORAGE
 	usb_stor_reset();
 #endif
+	if (CONFIG_IS_ENABLED(BOOTSTD)) {
+		int ret;
+
+		ret = bootdev_unhunt(UCLASS_USB);
+		if (IS_ENABLED(CONFIG_BOOTSTD_FULL) && ret && ret != -EALREADY)
+			printf("failed to unhunt USB (err=%dE)\n", ret);
+	}
 	uc_priv->companion_device_count = 0;
 	usb_started = 0;