Fix the QuantizedAVX2 build issue (#26854)
Summary:
The QuantizedAVx2 does not support the int32 type. We switch to use at::quantize_vec function instead.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/26854
Differential Revision: D17609872
Pulled By: llyfacebook
fbshipit-source-id: b4a77d93ce0ebfef696506b5cdbe3e91fe44bb36
