drm/doc: Improve ioctl/fops docs a bit more

I spotted a markup issue, plus adding the descriptions in drm_driver.
Plus a few more links while at it.

I'm still mildly unhappy with the split between fops and ioctls, but I
still think having the ioctls in the uapi chapter makes more sense. Oh
well ...

v2: Rebase.

v3: Move misplace hunk to the right patch.

Cc: Stefan Agner <stefan@agner.ch>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170531092045.3950-1-daniel.vetter@ffwll.ch
diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
index e4de59b..f495eee 100644
--- a/include/drm/drm_drv.h
+++ b/include/drm/drm_drv.h
@@ -515,8 +515,26 @@ struct drm_driver {
 	char *date;
 
 	u32 driver_features;
+
+	/**
+	 * @ioctls:
+	 *
+	 * Array of driver-private IOCTL description entries. See the chapter on
+	 * :ref:`IOCTL support in the userland interfaces
+	 * chapter<drm_driver_ioctl>` for the full details.
+	 */
+
 	const struct drm_ioctl_desc *ioctls;
+	/** @num_ioctls: Number of entries in @ioctls. */
 	int num_ioctls;
+
+	/**
+	 * @fops:
+	 *
+	 * File operations for the DRM device node. See the discussion in
+	 * :ref:`file operations<drm_driver_fops>` for in-depth coverage and
+	 * some examples.
+	 */
 	const struct file_operations *fops;
 
 	/* Everything below here is for legacy driver, never use! */