i2c-davinci: convert clock usage after clkdev conversion

DaVinci core code has converted to the new clkdev API so
clock name strings are not needed.  Instead, just the a
'struct device' pointer is needed.
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

drivers/i2c/busses/i2c-davinci.c

@@ -523,7 +523,7 @@ static int davinci_i2c_probe(struct platform_device *pdev)
 	dev->irq = irq->start;
 	platform_set_drvdata(pdev, dev);
 
-	dev->clk = clk_get(&pdev->dev, "I2CCLK");
+	dev->clk = clk_get(&pdev->dev, NULL);
 	if (IS_ERR(dev->clk)) {
 		r = -ENODEV;
 		goto err_free_mem;