The driver calls dma_set_coherent_mask() but never dma_set_mask(),
leaving the streaming DMA mask at the bus default. On the non-coherent
EN7581 platform (Cortex-A53), this causes the NPU mailbox to hang
after approximately 41 calls when using streaming DMA mappings.
Replace dma_set_coherent_mask() with dma_set_mask_and_coherent() to
set both the streaming and coherent DMA masks, matching standard
driver practice.