X87: Use IC register definitions in platform files.

port r22035

original commit message:
  Use IC register definitions in platform files.

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/356133005

Patch from Chunyang Dai <chunyang.dai@intel.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22047 ce2b1a6d-e550-0410-aec6-3dcde31c8c00