iio: gyro: adis16136: remove duplicated include from adis16136.c

Remove duplicated include.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/gyro/adis16136.c

@@ -22,7 +22,6 @@
 #include <linux/iio/buffer.h>
 #include <linux/iio/imu/adis.h>
 
-#include <linux/iio/iio.h>
 #include <linux/debugfs.h>
 
 #define ADIS16136_REG_FLASH_CNT		0x00