usb: host: ehci-hcd: change trace level for phy errors managed by uclass

As the error message is now displayed by generic phy functions,
the pr_err can be change to pr_debug.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index f79f063..8933f60 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -1762,13 +1762,13 @@
 	} else {
 		ret = generic_phy_init(phy);
 		if (ret) {
-			dev_err(dev, "failed to init usb phy\n");
+			dev_dbg(dev, "failed to init usb phy\n");
 			return ret;
 		}
 
 		ret = generic_phy_power_on(phy);
 		if (ret) {
-			dev_err(dev, "failed to power on usb phy\n");
+			dev_dbg(dev, "failed to power on usb phy\n");
 			return generic_phy_exit(phy);
 		}
 	}
@@ -1786,13 +1786,13 @@
 	if (generic_phy_valid(phy)) {
 		ret = generic_phy_power_off(phy);
 		if (ret) {
-			dev_err(dev, "failed to power off usb phy\n");
+			dev_dbg(dev, "failed to power off usb phy\n");
 			return ret;
 		}
 
 		ret = generic_phy_exit(phy);
 		if (ret) {
-			dev_err(dev, "failed to power off usb phy\n");
+			dev_dbg(dev, "failed to power off usb phy\n");
 			return ret;
 		}
 	}