DMA-API: dma: pl08x: add dma_set_mask_and_coherent() call

The DMA API requires drivers to call the appropriate dma_set_mask()
functions before doing any DMA mapping.  Add this required call to
the AMBA PL08x driver.

Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>