Documentation: devlink: add missing toc entry for etas_es58x devlink doc

toc entry is missing for etas_es58x devlink doc and triggers this warning:

  Documentation/networking/devlink/etas_es58x.rst: WARNING: document isn't included in any toctree

Add the missing toc entry.

Fixes: 9f63f96 ("Documentation: devlink: add devlink documentation for the etas_es58x driver")
Signed-off-by: Vincent Mailhol <[email protected]>
Link: https://lore.kernel.org/all/[email protected]
Reported-by: Stephen Rothwell <[email protected]>
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Marc Kleine-Budde <[email protected]>

Author: vincent-mailhol

Documentation/networking/devlink/index.rst

@@ -50,6 +50,7 @@ parameters, info versions, and other features it supports.
    :maxdepth: 1
 
    bnxt
+   etas_es58x
    hns3
    ionic
    ice