[MIPS] Threaten removal of code for NEC DDB5074 and DDB5476 evaluation boards.

What:   Support for NEC DDB5074 and DDB5476 evaluation boards.
When:   June 2006
Why:    Board specific code doesn't build anymore since ~2.6.0 and no
        users have complained indicating there is no more need for these
        boards.  This should really be considered a last call.
Who:    Ralf Baechle <ralf@linux-mips.org>