gpio: ftgpio010: Drop of_gpio.h include

This driver does not make use of the functions in
<linux/of_gpio.h> so drop this include.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-ftgpio010.c

@@ -14,7 +14,6 @@
 #include <linux/io.h>
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
-#include <linux/of_gpio.h>
 #include <linux/bitops.h>
 
 /* GPIO registers definition */