ppc4xx: Remove ML2 board support

As the board seems to be unmaintained for some time, lets remove
the support in mainline completely.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Peter De Schrijver <p2@mind.be>
Acked-by: Marek Vasut <marex@denx.de>
11 files changed