Kill TH(C)Blas kwarg_only declarations. (#25607)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/25607
Since we don't generate these as end-user bindings, and we no longer reorder based on this property, we can just get rid of the property.
Test Plan: Imported from OSS
Differential Revision: D17172500
Pulled By: gchanan
fbshipit-source-id: f84fd8bb2b13598501897f56871b21339585d844