[PyTorch Edge][QNNPack] Refactor Computing Step Dimensions (#69310)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/69310
Extract computing step height and step width into helper function and store them in operator struct since the same calculation is used in many places before this diff.
ghstack-source-id: 146346783
Test Plan: Phabricator tests
Reviewed By: kimishpatel
Differential Revision: D32553327
fbshipit-source-id: e5bf07416f4c1ccde9975f835767392ad7a851c1