Merge branch 'netpoll-untangle-netconsole-and-netpoll'

Breno Leitao says:

====================
netpoll: Untangle netconsole and netpoll

Initially netpoll and netconsole were created together, and some
functions are in the wrong file. Seperate netconsole-only functions
in netconsole, avoiding exports.

1. Expose netpoll logging macros in the public header to enable consistent
   log formatting across netpoll consumers.

2. Relocate netconsole-specific functions from netpoll to the netconsole
   module where they are actually used, reducing unnecessary coupling.

3. Remove unnecessary function exports

4. Rename netpoll parsing functions in netconsole to better reflect their
   specific usage.

5. Create a test to check that cmdline works fine. This was in my todo
   list since [1], this was a good time to add it here to make sure this
   patchset doesn't regress.

PS: The code was split in a way that it is easy to review. When copying
the functions from netpoll to netconsole, I do not change than other
than adding `static`. This will make checkpatch unhappy, but, further
patches will address the issues. It is done this way to make it easy for
reviewers.

Link: https://lore.kernel.org/netdev/Z36TlACdNMwFD7wv@dev-ushankar.dev.purestorage.com/
v2: https://lore.kernel.org/20250611-rework-v2-0-ab1d92b458ca@debian.org
v1: https://lore.kernel.org/20250610-rework-v1-0-7cfde283f246@debian.org
====================

Link: https://patch.msgid.link/20250613-rework-v3-0-0752bf2e6912@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>