Documentation/mainboard: Fix index

Remove duplicate headings, move vendor sections that were placed
amidst other vendor hierarchies, and while we are at it, sort it
alphabetically.

Change-Id: I1f684deac3bbf98e8584089be05daf1c73e74a2d
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35462
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Michael Niewöhner
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

0 files changed, 0 insertions, 0 deletions