rust: drm: gpuvm: update DriverGpuVm for DeviceContext

Since the introduction of DeviceContext, there is no longer a single
driver object type to equate with the GPUVM object type.

Instead of threading DeviceContext through GPUVM, remove the strict
identity between DriverGpuVm::Object and drm::Driver::Object and
instead tighten the requirement that the DriverGpuVm::Object be an
allocatable GEM object associated with the same DRM driver.

Also, make GpuVm::new() generic over DeviceContext so it can accept a
drm::Device<T::Driver, Ctx>.

Fixes: 0023a1e8d0 ("rust/drm/gem: Use DeviceContext with GEM objects")
Signed-off-by: Deborah Brouwer <deborah.brouwer@collabora.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://patch.msgid.link/20260610-gpuvm_device_context_v1-v1-1-01a890b17448@collabora.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

rust/kernel/drm/gpuvm/mod.rs

@@ -116,9 +116,9 @@ const fn vtable() -> &'static bindings::drm_gpuvm_ops {
 
     /// Creates a GPUVM instance.
     #[expect(clippy::new_ret_no_self)]
-    pub fn new<E>(
+    pub fn new<E, Ctx: drm::DeviceContext>(
         name: &'static CStr,
-        dev: &drm::Device<T::Driver>,
+        dev: &drm::Device<T::Driver, Ctx>,
         r_obj: &T::Object,
         range: Range<u64>,
         reserve_range: Range<u64>,
@@ -252,10 +252,10 @@ fn raw_resv(&self) -> *mut bindings::dma_resv {
 /// The manager for a GPUVM.
 pub trait DriverGpuVm: Sized + Send {
     /// Parent `Driver` for this object.
-    type Driver: drm::Driver<Object = Self::Object>;
+    type Driver: drm::Driver;
 
     /// The kind of GEM object stored in this GPUVM.
-    type Object: IntoGEMObject;
+    type Object: drm::driver::AllocImpl<Driver = Self::Driver>;
 
     /// Data stored with each [`struct drm_gpuva`](struct@GpuVa).
     type VaData;