Move vhost-user-gpu from staging to main directory

The CLI interface should be stable now and coverage is good. Support
for more backends as described in the README is comming later.

Note that this decreases the test coverage in the staging directory from
82.43% to 74.62%.

Signed-off-by: Matej Hrica <mhrica@redhat.com>

vhost-device-gpu/Cargo.toml

@@ -0,0 +1,45 @@
+[package]
+name = "vhost-device-gpu"
+version = "0.1.0"
+authors = ["Dorinda Bassey <dbassey@redhat.com>", "Matej Hrica <mhrica@redhat.com>"]
+description = "A virtio-gpu device using the vhost-user protocol."
+repository = "https://github.com/rust-vmm/vhost-device"
+readme = "README.md"
+keywords = ["gpu", "vhost", "vhost-user", "virtio"]
+categories = ["multimedia::video", "virtualization"]
+license = "Apache-2.0 OR BSD-3-Clause"
+edition = "2021"
+publish = false
+# "Features enabled on platform-specific dependencies for target architectures not currently being built are ignored."
+# See <https://doc.rust-lang.org/cargo/reference/features.html#feature-resolver-version-2>
+resolver = "2"
+
+[features]
+default = ["gfxstream"]
+xen = ["vm-memory/xen", "vhost/xen", "vhost-user-backend/xen"]
+gfxstream = ["rutabaga_gfx/gfxstream"]
+
+[dependencies]
+clap = { version = "4.5", features = ["derive"] }
+env_logger = "0.11.6"
+libc = "0.2"
+log = "0.4"
+
+[target.'cfg(not(target_env = "musl"))'.dependencies]
+rutabaga_gfx = { version = "0.1.5", features = ["virgl_renderer"] }
+thiserror = "2.0.11"
+vhost = { version = "0.13.0", features = ["vhost-user-backend"] }
+vhost-user-backend = "0.17"
+virtio-bindings = "0.2.2"
+virtio-queue = "0.14.0"
+vm-memory = "0.16.1"
+vmm-sys-util = "0.12.1"
+bitflags = "2.8.0"
+
+[dev-dependencies]
+assert_matches = "1.5"
+mockall = "0.13.0"
+rusty-fork = "0.3.0"
+tempfile = "3.16"
+virtio-queue = { version = "0.14", features = ["test-utils"] }
+vm-memory = { version = "0.16.1", features = ["backend-mmap", "backend-atomic"] }