-Downscaled / quantized value is calculated using the formula
x' = (x / scale_factor) + zero_point. As it stands, the micro-kernels
for these APIs only support scaling.
Zero point addition is implemented as part of this commit, with it
being fused as part of the downscale post-op in the micro-kernel. The
zero point input is a vector of int8 values, and currently only vector
based zero point addition is supported.
-Bench enhancements to test/benchmark zero point addition.
AMD-Internal: [SWLCSG-2332]
Change-Id: I96b4b1e5a384a4683b50ca310dcfb63debb1ebea