Update on "Add update_quantized_cache op"

Why?
- ton of copies due to functionalization
- mutable buffer support without such custom inplace ops will results in giant
  copies at the end
- Making inplace ops work will likely take longer and not clear safe path

Differential Revision: [D62301838](https://our.internmc.facebook.com/intern/diff/D62301838/)

[ghstack-poisoned]

Author: kimishpatel