rust: collect file dependencies for clippy

Previously, the clippy rule did not keep track of the source files for
which a modification would require the target to be rebuilt. Similarly
to the rustc rule, ensure that we capture all the dependencies via the
dep-info output.

Bug: 181298002
Test: m libkeystore2; inspect generated .clippy.d
Change-Id: Icfc7074e1fca38f7782544e6c436ffbfc6c9b4e0