PPC4xx: Remove quad100hd board

The quad100hd has been unmaintained and dead ever since it's been
added some 6 years ago.  Remove it.

Also update README.scrapyard and insert some commit IDs for removed
boards.

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Stefan Roese <sr@denx.de>
Cc: Gary Jennejohn <gljennjohn@googlemail.com>
6 files changed