i2c: imx: make bitrate an u32 type

sparse found this assignment of u32 to an int. Fix it:

drivers/i2c/busses/i2c-imx.c:540:56: warning: incorrect type in argument 3 (different signedness)

and also fix the type in platform_data. All current users use values
which fit into the old and new type, so it is a safe change.

Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>
Reviewed-by: Richard Zhao <richard.zhao@freescale.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index dd2a083..90460dd 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -471,8 +471,8 @@
 	struct imxi2c_platform_data *pdata = pdev->dev.platform_data;
 	struct pinctrl *pinctrl;
 	void __iomem *base;
-	int irq, bitrate;
-	int ret;
+	int irq, ret;
+	u32 bitrate;
 
 	dev_dbg(&pdev->dev, "<%s>\n", __func__);