Documentation: devlink: add devlink documentation for the etas_es58x driver

List all the version information reported by the etas_es58x driver
through devlink. Also, update MAINTAINERS with the newly created file.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20221130174658.29282-8-mailhol.vincent@wanadoo.fr
[mkl: fixed version information table: "bl" -> "fw.bootloader"
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>