Update the 4.20 release notes to the final post-release version.
This fixes a few typos, updates the statistics to include the final few
patches, and adds a note about the licensing issues which required a
version bump to 4.20.1.
Signed-off-by: Martin Roth <gaumless@gmail.com>
Change-Id: I350535b8aa531642e161f1cad4752452f9171647
Reviewed-on: https://review.coreboot.org/c/coreboot/+/75636
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>
Reviewed-by: Nico Huber <nico.h@gmx.de>