Add missing attr in LazyModuleMixin doc (#53363)
Summary:
To fix some rendering issues.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/53363
Reviewed By: izdeby
Differential Revision: D26884560
Pulled By: albanD
fbshipit-source-id: fedc9c9972a6c68f311c6aafcbb33a3a881bbcd2
