usb: ehci: Correct a missing hypen in an error message

Add a hyphen to correct the grammar.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index bf02221..b040f12 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -321,7 +321,7 @@
 		struct udevice *dev = parent;
 
 		if (device_get_uclass_id(dev->parent) != UCLASS_USB_HUB) {
-			printf("ehci: Error cannot find high speed parent of usb-1 device\n");
+			printf("ehci: Error cannot find high-speed parent of usb-1 device\n");
 			return;
 		}