dmaengine: pl08x: Add support for the DMA slave map

This patch adds support for the new channel request API introduced
in commit a8135d0d
"dmaengine: core: Introduce new, universal API to request a channel".

param field of struct dma_slave_map type entries in the platform
data structure should be pointing to struct pl08x_channel_data
of related DMA channel.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>