powerpc: mpc5xxx: remove galaxy5200 board support

This has not been converted to Generic Board, so should be removed.
(See doc/README.generic-board for details.)

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Eric Millbrandt <emillbrandt@dekaresearch.com>
9 files changed