netconsole: introduce 'release' as a new sysdata field

This commit adds a new feature to the sysdata structure, allowing the
kernel release/version to be appended as part of sysdata. Additionally,
it updates the logic to count this new field as a used entry when
enabled.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250314-netcons_release-v1-1-07979c4b86af@debian.org


Signed-off-by: Paolo Abeni <pabeni@redhat.com>