dmaengine: make slave address physical

The slave dmaengine semantics required the client to map dma
addresses and pass DMA address to dmaengine drivers. This
was a convenient notion coming from generic dma offload cases
where dmaengines are interchangeable and client is not aware of
which engine to map to.

But in case of slave, we know the dmaengine and always use a
specific one. Further the IOMMU cases can lead to failure of this
notion, so make this as physical address and now dmaengine driver
will do the required mapping.

Original-patch-by: Linus Walleij <linus.walleij@linaro.org>
Original-patch-Acked-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>