Details:
- In WOQ, if m = 4, special case kernels are added where
s4->bf16 conversion happens inside the compute kernel and
packing is avoided. For all other cases, B matrix is
dequantized and packed at KC loop level and native bf16
kernels are re-used at compute level.
- Fixes in bench to avoid accuracy failures when datatype of
output is bf16.
Change-Id: Ie8db42da536891693d5e82a5336b66514a50ccb2
2e1cc2f14a