AUTHORS: Update Authors list from original to 4.21 release

This commit adds all the individual authors and their companies, as
determined by their email addresses. Because it is very difficult to
figure out if an individual is doing work on their own, or on the
company's behalf, both are being added.

This will be maintained as a part of the release process from here on.

Signed-off-by: Martin Roth <gaumless@gmail.com>
Change-Id: Id199f1c5d49d74290002d46dbdfc1d33b0fb55e5
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78286
Reviewed-by: Eric Lai <ericllai@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>