accel: Link to compute accelerator subsystem intro

Commit 2c204f3d ("accel: add dedicated minor for accelerator
devices") adds link to accelerator nodes section of DRM internals doc
(Documentation/gpu/drm-internals.rst), but the target doesn't exist.
Instead, there is only an introduction doc for computer accelerator
subsytem.

Link to that doc until there is documentation of accelerator internals.

Fixes: 2c204f3d ("accel: add dedicated minor for accelerator devices")
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

include/drm/drm_file.h

@@ -408,7 +408,8 @@ static inline bool drm_is_render_client(const struct drm_file *file_priv)
  * Returns true if this is an open file of the compute acceleration node, i.e.
  * &drm_file.minor of @file_priv is a accel minor.
  *
- * See also the :ref:`section on accel nodes <drm_accel_node>`.
+ * See also :doc:`Introduction to compute accelerators subsystem
+ * </accel/introduction>`.
  */
 static inline bool drm_is_accel_client(const struct drm_file *file_priv)
 {