Backend: Optimization internal math, use mad
Backend: Optimization internal math, use mad

Affected functions:
__gen_ocl_internal_log
__gen_ocl_internal_log10
__gen_ocl_internal_log2
__gen_ocl_internal_log_valid
__kernel_sinf
__kernel_cosf
__gen_ocl_internal_cbrt
__gen_ocl_internal_asinh
__gen_ocl_internal_atan
__gen_ocl_asin_util
tan
log1p
lgamma_r
lgamma

Signed-off-by: Grigore Lupescu <grigore.lupescu at intel.com>
Reviewed-by: Ruiling Song <286a174c1339c6eff91abc41c3a1012c95030c95@intel.com>

wdv4758h/beignet,wdv4758h/beignet,wdv4758h/beignet,wdv4758h/beignet,wdv4758h/beignet