i2c: st: add include for pinctrl

The driver uses pinctrl directly and thus should include the appropriate
header. Sort the headers while we are here to have a better view what is
included and what is not.

Reported-by: Pascal Huerst <[e-mail]>
Signed-off-by: Wolfram Sang <[e-mail]>

drivers/i2c/busses/i2c-st.c

···
  * published by the Free Software Foundation.
  */
 
-#include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/i2c.h>
 #include <linux/clk.h>
-#include <linux/io.h>
 #include <linux/delay.h>
-#include <linux/interrupt.h>
 #include <linux/err.h>
-#include <linux/of.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
+#include <linux/of.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
 
 /* SSC registers */
 #define SSC_BRG				0x000