drop broken recipes and bogus README.sources

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
edison: drop bogus TUNE_CC_ARGS

Stack realignment is only needed when using legacy binaries, which we do not
want to support in OE.

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>