This patch replaces the BOARD_REVISION variable in include/config.mk
by a using a temporary include file in the platform directory.

The former way does not work anymore and the latter is also used by
some other boards.
Signed-off-by: NMatthias Fuchs <matthias.fuchs@esd-electronics.com>
Signed-off-by: NStefan Roese <sr@denx.de>