usb: ehci-atmel: Remove unnecessary clock calling

Due to the peripheral clock driver improvement, remove the
unnecessary clock calling.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: Andreas Bießmann <andreas@biessmann.org>
diff --git a/drivers/usb/host/ehci-atmel.c b/drivers/usb/host/ehci-atmel.c
index 2b138c5..a5c6d34 100644
--- a/drivers/usb/host/ehci-atmel.c
+++ b/drivers/usb/host/ehci-atmel.c
@@ -56,9 +56,7 @@
 
 static int ehci_atmel_enable_clk(struct udevice *dev)
 {
-	struct udevice *dev_clk;
 	struct clk clk;
-	int periph;
 	int ret;
 
 	ret = clk_get_by_index(dev, 0, &clk);
@@ -73,19 +71,6 @@
 	if (ret)
 		return -EINVAL;
 
-	periph = fdtdec_get_uint(gd->fdt_blob, clk.dev->of_offset, "reg", -1);
-	if (periph < 0)
-		return -EINVAL;
-
-	dev_clk = dev_get_parent(clk.dev);
-	if (!dev_clk)
-		return -ENODEV;
-
-	ret = clk_request(dev_clk, &clk);
-	if (ret)
-		return ret;
-
-	clk.id = periph;
 	ret = clk_enable(&clk);
 	if (ret)
 		return ret;