drm: nova: update ARef import from sync::aref

Update nova to import `ARef` from `sync::aref` instead of `types`.

This aligns with the ongoing effort to move `ARef` and
`AlwaysRefCounted` to sync.

Suggested-by: Benno Lossin <lossin@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1173
Signed-off-by: Shankari Anand <shankari.ak0208@gmail.com>
Link: https://lore.kernel.org/r/20250716090941.811418-1-shankari.ak0208@gmail.com
[ Alter subject and commit message to be nova specific. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

drivers/gpu/drm/nova/driver.rs

@@ -1,6 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0
 
-use kernel::{auxiliary, c_str, device::Core, drm, drm::gem, drm::ioctl, prelude::*, types::ARef};
+use kernel::{
+    auxiliary, c_str, device::Core, drm, drm::gem, drm::ioctl, prelude::*, sync::aref::ARef,
+};
 
 use crate::file::File;
 use crate::gem::NovaObject;

drivers/gpu/drm/nova/gem.rs

@@ -4,7 +4,7 @@ use kernel::{
     drm,
     drm::{gem, gem::BaseObject},
     prelude::*,
-    types::ARef,
+    sync::aref::ARef,
 };
 
 use crate::{