i2c: xiic: defer the probe if clock is not found

It's not always the case that clock is already available when i2c
driver get probed at the first time, e.g. the clock is provided by
clock wizard which may be probed after i2c driver. So let's defer
the probe when devm_clk_get() call fails and give it chance to
try later.
Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-xiic.c

@@ -788,7 +788,8 @@ static int xiic_i2c_probe(struct platform_device *pdev)
 
 	i2c->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(i2c->clk)) {
-		dev_err(&pdev->dev, "input clock not found.\n");
+		if (PTR_ERR(i2c->clk) != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "input clock not found.\n");
 		return PTR_ERR(i2c->clk);
 	}
 	ret = clk_prepare_enable(i2c->clk);