usb: dwc2: gadget: Do not fail probe if there isn't a clock node

Since the dwc2 hcd driver is currently not looking for a clock node during
init, we should not completely fail if there isn't a clock provided.
By assigning clk = NULL, this allows the driver, when configured for dual-role
mode, to be able to continue loading the host portion of the driver when
a clock node is not specified.
Acked-by: NPaul Zimmerman <paulz@synopsys.com>
Signed-off-by: NDinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

drivers/usb/dwc2/gadget.c

@@ -3431,6 +3431,7 @@ int dwc2_gadget_init(struct dwc2_hsotg *hsotg, int irq)
 
 	hsotg->clk = devm_clk_get(dev, "otg");
 	if (IS_ERR(hsotg->clk)) {
+		hsotg->clk = NULL;
 		dev_err(dev, "cannot get otg clock\n");
 		return PTR_ERR(hsotg->clk);
 	}