Pass manager should take in type[pass] instead of pass instance (#1029)

Summary:
Pull Request resolved: https://github.com/pytorch/executorch/pull/1029

Fixing the typing annotations. XNNPACK pass manager should take in a Type[PassType] instead of a PassType since we are passing in a class instead of a Pass Instance

Reviewed By: kirklandsign

Differential Revision: D49710932

fbshipit-source-id: db291f7c4425e10b17ee50881f5c4b48d2ea5db6