rust: dma: convert the read/write macros to return Result

rust: dma: convert the read/write macros to return Result

We could do better here by having the macros return `Result`,
so that we don't have to wrap these calls in a closure for
validation which is confusing.

Co-developed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/rust-for-linux/87h63qhz4q.fsf@kernel.org/
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@gmail.com>
Link: https://lore.kernel.org/r/20250602085444.1925053-3-abdiel.janulgue@gmail.com
[ Fix line length in dma_read!(). - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>