i2c: Include linux/of.h header

'of_match_ptr' is defined in linux/of.h. Include it explicitly to
avoid build breakage in the future.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-gpio.c

@@ -15,6 +15,7 @@
 #include <linux/slab.h>
 #include <linux/platform_device.h>
 #include <linux/gpio.h>
+#include <linux/of.h>
 #include <linux/of_gpio.h>
 
 struct i2c_gpio_private_data {

drivers/i2c/busses/i2c-pnx.c

@@ -23,6 +23,7 @@
 #include <linux/err.h>
 #include <linux/clk.h>
 #include <linux/slab.h>
+#include <linux/of.h>
 
 #define I2C_PNX_TIMEOUT_DEFAULT		10 /* msec */
 #define I2C_PNX_SPEED_KHZ_DEFAULT	100

drivers/i2c/busses/i2c-s3c2410.c

@@ -36,6 +36,7 @@
 #include <linux/cpufreq.h>
 #include <linux/slab.h>
 #include <linux/io.h>
+#include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <linux/pinctrl/consumer.h>
 

drivers/i2c/busses/i2c-xiic.c

@@ -40,6 +40,7 @@
 #include <linux/i2c-xiic.h>
 #include <linux/io.h>
 #include <linux/slab.h>
+#include <linux/of.h>
 
 #define DRIVER_NAME "xiic-i2c"
 

drivers/i2c/muxes/i2c-mux-pinctrl.c

@@ -24,6 +24,7 @@
 #include <linux/i2c-mux-pinctrl.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
+#include <linux/of.h>
 
 struct i2c_mux_pinctrl {
 	struct device *dev;