IIO: Move core headers to include/linux/iio

Step 1 in moving the IIO core out of staging.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/iio/imu/adis16400_ring.c b/drivers/staging/iio/imu/adis16400_ring.c
index d964004..e43c0e2 100644
--- a/drivers/staging/iio/imu/adis16400_ring.c
+++ b/drivers/staging/iio/imu/adis16400_ring.c
@@ -6,9 +6,9 @@
 #include <linux/bitops.h>
 #include <linux/export.h>
 
-#include "../iio.h"
+#include <linux/iio/iio.h>
 #include "../ring_sw.h"
-#include "../trigger_consumer.h"
+#include <linux/iio/trigger_consumer.h>
 #include "adis16400.h"
 
 /**