It is to prepare for Xv on Ivybridge. The difference from Sandybridge
is that all message payload must be in GRF registers instead of MRF registers
on Ivybridge. We will only redefine some M4 macros for Ivybridge
Signed-off-by: Xiang, Haihao <haihao.xiang@intel.com>
Xiang, Haihao