dmaengine: owl: Use devm_platform_ioremap_resource() in owl_dma_probe()

Simplify this function implementation by using a known wrapper function.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Link: https://lore.kernel.org/r/d36b6a6c-2e3d-8d68-6ddc-969a377ca3b2@web.de
Signed-off-by: Vinod Koul <vkoul@kernel.org>