floss: Remove duplicate topshim address conversions

Get rid of duplicated to_rust_address and from_rust_address conversions
in various topshim files. All the implementations now share a single
conversion from common/utils.h.

Bug: 204488136
Tag: #floss
Test: Build on ChromeOS + Android presubmit build
Change-Id: I37774e37ea3370b76f813af059d6e93cc7aa9dc6