rust: platform: implement the dma::Device trait

The platform bus is potentially capable of performing DMA, hence implement
the `dma:Device` trait for `platform::Device`.

Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250716150354.51081-5-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

Author: Danilo Krummrich

rust/kernel/platform.rs

@@ -231,6 +231,8 @@ impl<Ctx: device::DeviceContext> Device<Ctx> {
 kernel::impl_device_context_deref!(unsafe { Device });
 kernel::impl_device_context_into_aref!(Device);
 
+impl crate::dma::Device for Device<device::Core> {}
+
 // SAFETY: Instances of `Device` are always reference-counted.
 unsafe impl crate::types::AlwaysRefCounted for Device {
     fn inc_ref(&self) {