MIPS: DEC: Update CPU overrides

Update CPU overrides for the DEC port with the recent additions, shaving
off some effectively dead code:

   text    data      bss      dec     hex filename
5586952  233132  5990368 11810452  b43694 vmlinux.32-old
5581248  233140  5990368 11804756  b42054 vmlinux.32-new

   text    data      bss      dec     hex filename
6036936  356648 10756544 17150128 105b0b0 vmlinux.64-old
6029896  360752 10756544 17147192 105a538 vmlinux.64-new

The data size increase is due to the special alignment requirement of
`init_thread_union' aka `.data..init_task' moving it up to the nearest
page boundary and making the amount of padding at its front rely on how
far within a page text ends.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10197/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>