iio: hid_Sensors: fix crash during trigger unregister

We can't store the trigger instance created by iio_trigger_alloc, in
trig field of iio_device structure. This needs to be stored in the
driver private data. Othewise it can result in crash during module
unload. Hence created a trig_ptr in the common data structure
for each HID sensor IIO driver and storing here.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/include/linux/hid-sensor-hub.h b/include/linux/hid-sensor-hub.h
index a265af2..206a2af 100644
--- a/include/linux/hid-sensor-hub.h
+++ b/include/linux/hid-sensor-hub.h
@@ -21,6 +21,8 @@
 
 #include <linux/hid.h>
 #include <linux/hid-sensor-ids.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
 
 /**
  * struct hid_sensor_hub_attribute_info - Attribute info
@@ -184,6 +186,7 @@
 	struct platform_device *pdev;
 	unsigned usage_id;
 	bool data_ready;
+	struct iio_trigger *trigger;
 	struct hid_sensor_hub_attribute_info poll;
 	struct hid_sensor_hub_attribute_info report_state;
 	struct hid_sensor_hub_attribute_info power_state;