dwc3-generic: Don't fail probe if clk/reset entries are absent

Some boards don't populate clk/reset entries as these are are optional
as per binding documentation. Therefore, don't fail driver probe if
clk/reset entries are absent in DT.

This fixes fastboot failures seen due to enabling of CONFIG_CLK on AM57xx

Fixes: e8e683d33b0c ("board: ti: am57xx-idk: Configure the CDCE913 clock synthesizer")
Reported-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
diff --git a/drivers/usb/dwc3/dwc3-generic.c b/drivers/usb/dwc3/dwc3-generic.c
index 023e953..24b320b 100644
--- a/drivers/usb/dwc3/dwc3-generic.c
+++ b/drivers/usb/dwc3/dwc3-generic.c
@@ -338,7 +338,7 @@
 	int ret;
 
 	ret = reset_get_bulk(dev, &glue->resets);
-	if (ret == -ENOTSUPP)
+	if (ret == -ENOTSUPP || ret == -ENOENT)
 		return 0;
 	else if (ret)
 		return ret;
@@ -358,7 +358,7 @@
 	int ret;
 
 	ret = clk_get_bulk(dev, &glue->clks);
-	if (ret == -ENOSYS)
+	if (ret == -ENOSYS || ret == -ENOENT)
 		return 0;
 	if (ret)
 		return ret;