Input: ilitek_ts_i2c - stop including gpio.h

The driver does not use legacy GPIO API, stop including this header.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/ZrAaHWNvaAfDlDfI@google.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/ilitek_ts_i2c.c

@@ -15,7 +15,6 @@
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
-#include <linux/gpio.h>
 #include <linux/gpio/consumer.h>
 #include <linux/errno.h>
 #include <linux/acpi.h>