cciss: add P700m to list of supported controllers

P700m support was added in:
  9cff3b38

Update cciss.txt to match.

Signed-off-by: dann frazier <dannf@hp.com>
Acked-by: Mike Miller <mike.miller@hp.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>