rust: remove unnecessary Cargo.toml metadata

Some items of Cargo.toml (readme, homepage, repository) are
only present because of clippy::cargo warnings being enabled in
rust/hw/char/pl011/src/lib.rs.  But these items are not
particularly useful and would be all the same for all Cargo.toml
files in the QEMU workspace.  Clean them up.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

rust/qemu-api-macros/Cargo.toml

@@ -4,10 +4,7 @@ version = "0.1.0"
 edition = "2021"
 authors = ["Manos Pitsidianakis <manos.pitsidianakis@linaro.org>"]
 license = "GPL-2.0-or-later"
-readme = "README.md"
-homepage = "https://www.qemu.org"
 description = "Rust bindings for QEMU - Utility macros"
-repository = "https://gitlab.com/qemu-project/qemu/"
 resolver = "2"
 publish = false
 keywords = []

rust/qemu-api-macros/README.md

@@ -1 +0,0 @@
-# `qemu-api-macros` - Utility macros for defining QEMU devices