docs: netdev: broaden mailbot to all MAINTAINERS

Reword slightly now that all MAINTAINERS have access to the commands.

Signed-off-by: Jakub Kicinski <[e-mail]>
Reviewed-by: Simon Horman <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

Documentation/process/maintainer-netdev.rst

···
 of communicating with the bot, the bot commands should be seen as metadata.
 
 The use of the bot is restricted to authors of the patches (the ``From:``
-header on patch submission and command must match!), maintainers themselves
-and a handful of senior reviewers. Bot records its activity here:
+header on patch submission and command must match!), maintainers of
+the modified code according to the MAINTAINERS file (again, ``From:``
+must match the MAINTAINERS entry) and a handful of senior reviewers.
+
+Bot records its activity here:
 
   https://patchwork.hopto.org/pw-bot.html