vhost-device-gpu: Rename feature flag

Rename the feature flag from 'gfxstream' to
'backend-gfxstream' for consistency with the
new 'backend-virgl' feature flag added.

This naming convention:
- Makes it clear these are backend selection features
- Provides consistent naming across backends
  (backend-virgl, backend-gfxstream)

Signed-off-by: Dorinda Bassey <[email protected]>

Author: Dorinda Bassey

vhost-device-gpu/Cargo.toml

@@ -14,9 +14,10 @@ edition = "2021"
 resolver = "2"
 
 [features]
-default = ["gfxstream"]
+default = ["backend-virgl", "backend-gfxstream"]
 xen = ["vm-memory/xen", "vhost/xen", "vhost-user-backend/xen"]
-gfxstream = ["rutabaga_gfx/gfxstream"]
+backend-gfxstream = ["rutabaga_gfx/gfxstream"]
+backend-virgl = ["dep:virglrenderer"]
 
 [dependencies]
 clap = { version = "4.5", features = ["derive"] }
@@ -25,8 +26,9 @@ libc = "0.2"
 log = "0.4"
 
 [target.'cfg(not(target_env = "musl"))'.dependencies]
-rutabaga_gfx = { version = "0.1.75", features = ["virgl_renderer"] }
+rutabaga_gfx = { version = "0.1.75"}
 thiserror = "2.0.17"
+virglrenderer = {version = "0.1.2", optional = true }
 vhost = { version = "0.14.0", features = ["vhost-user-backend"] }
 vhost-user-backend = "0.20"
 virtio-bindings = "0.2.5"