i2c: jz4780: really prevent potential division by zero

Make sure we avoid a division-by-zero OOPS in case clock-frequency is
set too low in DT. Add missing '\n' while we are here.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: NAxel Lin <axel.lin@ingics.com>

drivers/i2c/busses/i2c-jz4780.c

@@ -771,11 +771,16 @@ static int jz4780_i2c_probe(struct platform_device *pdev)
 	ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
 				   &clk_freq);
 	if (ret) {
-		dev_err(&pdev->dev, "clock-frequency not specified in DT");
+		dev_err(&pdev->dev, "clock-frequency not specified in DT\n");
 		goto err;
 	}
 
 	i2c->speed = clk_freq / 1000;
+	if (i2c->speed == 0) {
+		ret = -EINVAL;
+		dev_err(&pdev->dev, "clock-frequency minimum is 1000\n");
+		goto err;
+	}
 	jz4780_i2c_set_speed(i2c);
 
 	dev_info(&pdev->dev, "Bus frequency is %d KHz\n", i2c->speed);