phy: bcm-ns-usb2: improve printing ref clk errors

Improve message & use dev_err_probe() helper which prints actual error
(helpful for debugging) and deals with -EPROBE_DEFER.

Signed-off-by: Rafał Miłecki <[e-mail]>
Reviewed-by: Florian Fainelli <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

drivers/phy/broadcom/phy-bcm-ns-usb2.c

···
 
 	usb2->ref_clk = devm_clk_get(dev, "phy-ref-clk");
 	if (IS_ERR(usb2->ref_clk)) {
-		dev_err(dev, "Clock not defined\n");
+		dev_err_probe(dev, PTR_ERR(usb2->ref_clk), "failed to get ref clk\n");
 		return PTR_ERR(usb2->ref_clk);
 	}