i2c: i2c-imx: Adapt the clock name to the new clock framework

With the new i.mx clock framework the i2c clock is registered as:

clk_register_clkdev(clk[i2c1_ipg_gate], NULL, "imx-i2c.0")

So we do not need to pass "i2c_clk" string and can use NULL instead.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>

[wsa: rebased on top of the devm-conversion]
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

drivers/i2c/busses/i2c-imx.c

@@ -514,7 +514,7 @@ static int __init i2c_imx_probe(struct platform_device *pdev)
 	}
 
 	/* Get I2C clock */
-	i2c_imx->clk = devm_clk_get(&pdev->dev, "i2c_clk");
+	i2c_imx->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(i2c_imx->clk)) {
 		dev_err(&pdev->dev, "can't get I2C clock\n");
 		return PTR_ERR(i2c_imx->clk);