docs: process: maintainer-pgp-guide: update kernel.org docs link

Update http link to the documentation about how to add a kernel.org UID to
the maintainer's key. Add missing SPDX-License-Identifier to fix a
checkpatch warning.

Signed-off-by: Amitabh Srivastava <amitabh@amidevlab.com>
Reviewed-by: Konstantin Ryabitsev <konstantin@linuxfoundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20260205115554.7795-1-amitabh@amidevlab.com>
This commit is contained in:
Amitabh Srivastava 2026-02-05 17:25:41 +05:30 • committed by Jonathan Corbet
commit 6c5c07bc85