rust: dma: implement `dma::Device` trait

rust: dma: implement `dma::Device` trait

Add a trait that defines the DMA specific methods of devices.

The `dma::Device` trait is to be implemented by bus device
representations, where the underlying bus is capable of DMA, such as
`pci::Device` or `platform::Device`.

Reviewed-by: Abdiel Janulgue <abdiel.janulgue@gmail.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250716150354.51081-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>