jimtcl: update config.guess / config.sub

Fixes:
http://autobuild.buildroot.net/results/284/284876bd649cab26e5ecd696c03c71c077ea7411/



The build system doesn't use autotools, but does use an old version of
gnuconfig which doesn't know all the architectures supported by Buildroot,
so update config.guess / config.sub like we do in pkg-autotools.mk

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>