remoteproc: da8xx: Use devm_rproc_add() helper

remoteproc: da8xx: Use devm_rproc_add() helper

Use the device lifecycle managed add function. This helps prevent mistakes
like deleting out of order in cleanup functions and forgetting to delete
on error paths.

As this now makes the IRQ free ordered correctly, we can drop that from
the remove() callback, which is now empty and can also be removed.

Signed-off-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/20250814135532.638040-3-afd@ti.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>