HSW: Corret the scratch buffer size calc and set the correct index in vfe state.

HSW: Corret the scratch buffer size calc and set the correct index in vfe state.

HSW's scratch buffer alignment and the index set in vfe state are different with IVB.
And when calc per thread's stack offset, will used R0.0's FFTID to, the define of
FFTID also changed in HSW.
With this patch, all utest pass.

Signed-off-by: Yang Rong <rong.r.yang@intel.com>
Reviewed-by: Junyan He <junyan.he@inbox.com>