Input: pixcir_i2c_ts - remove unneeded gpio.h header file

The touchscreen device is a GPIO consumer, not a GPIO controller,
so there is no need to include <linux/gpio.h>.

Remove the unneeded header file.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Roger Quadros <rogerq@ti.com>
Tested-by: Michal Vokáč <michal.vokac@ysoft.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>