Staging: iio: accel: adis16201: Remove unused headers

Remove few unused headers files since the adis core handles the buffer and
sysfs support.

Signed-off-by: Himanshu Jha <himanshujha199640@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/staging/iio/accel/adis16201.c

@@ -6,7 +6,6 @@
  * Licensed under the GPL-2 or later.
  */
 
-#include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -16,8 +15,6 @@
 #include <linux/sysfs.h>
 
 #include <linux/iio/iio.h>
-#include <linux/iio/sysfs.h>
-#include <linux/iio/buffer.h>
 #include <linux/iio/imu/adis.h>
 
 #define ADIS16201_STARTUP_DELAY_MS			220