media: ov13858: Add implementation for events

Use v4l2 control API helpers to support the events.

Fixes v4l2-compliance:

test VIDIOC_(UN)SUBSCRIBE_EVENT/DQEVENT: FAIL

Signed-off-by: Ricardo Ribalda <[e-mail]>
Signed-off-by: Sakari Ailus <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/i2c/ov13858.c

···
 #include <linux/pm_runtime.h>
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-device.h>
+#include <media/v4l2-event.h>
 #include <media/v4l2-fwnode.h>
 
 #define OV13858_REG_VALUE_08BIT		1
···
 	return 0;
 }
 
+static const struct v4l2_subdev_core_ops ov13858_core_ops = {
+	.log_status = v4l2_ctrl_subdev_log_status,
+	.subscribe_event = v4l2_ctrl_subdev_subscribe_event,
+	.unsubscribe_event = v4l2_event_subdev_unsubscribe,
+};
+
 static const struct v4l2_subdev_video_ops ov13858_video_ops = {
 	.s_stream = ov13858_set_stream,
 };
···
 };
 
 static const struct v4l2_subdev_ops ov13858_subdev_ops = {
+	.core = &ov13858_core_ops,
 	.video = &ov13858_video_ops,
 	.pad = &ov13858_pad_ops,
 	.sensor = &ov13858_sensor_ops,
···
 
 	/* Initialize subdev */
 	ov13858->sd.internal_ops = &ov13858_internal_ops;
-	ov13858->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	ov13858->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE |
+			     V4L2_SUBDEV_FL_HAS_EVENTS;
 	ov13858->sd.entity.ops = &ov13858_subdev_entity_ops;
 	ov13858->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;