QNNPACK: Add support for dynamic quantization.
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/31896
Test Plan: Added new tests to QNNPACK's test suite to cover the new use case. All new tests are passing.
Reviewed By: supriyar
Differential Revision: D19443250
Pulled By: AshkanAliabadi
fbshipit-source-id: fa7b1cffed7266a3c198eb591d709f222141a152
