Remove legacy NAND and disk on chip references from boards.

board/delta/nand.c

board/esd/common/auto_update.c

board/g2000/g2000.c

board/netphone/netphone.c

board/netta/netta.c

board/netta2/netta2.c

board/netvia/netvia.c

board/omap2420h4/omap2420h4.c

board/samsung/smdk6400/smdk6400.c

board/sixnet/sixnet.c

board/stxxtc/stxxtc.c

board/zylonite/nand.c

include/configs/BMW.h

include/configs/CATcenter.h

include/configs/CPU86.h

include/configs/CPU87.h

include/configs/G2000.h

include/configs/GEN860T.h

include/configs/MIP405.h

include/configs/NETPHONE.h