[MIPS] Remove dead DECstation boot code

Code in arch/mips/dec/boot/ has been dead for long.  Let's get rid of it
before some epidemic spreads.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
3 files changed