Remove svn:externals that pull in all kinds of useful tools that

Remove svn:externals that pull in all kinds of useful tools that
are not needed for building coreboot.

The website tells you where to get them individually.

Signed-off-by: Patrick Georgi <patrick.georgi@coresystems.de>
Acked-by: Stefan Reinauer <stepan@coresystems.de>
Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Peter Stuge <peter@stuge.se>
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@4725 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1