dmaengine: dw-axi-dmac: Support of_dma_controller_register()

Add support for of_dma_controller_register() so that DMA clients
can pass in device handshake number to the AxiDMA driver.

DMA clients shall code the device handshake number in the Device tree.
When DMA activities are needed, DMA clients shall invoke OF helper
function to pass in the device handshake number to the AxiDMA.

Without register to the of_dma_controller_register(), data transfer
between memory to device and device to memory operations would failed.

Signed-off-by: Sia Jee Heng <jee.heng.sia@intel.com>
Tested-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Link: https://lore.kernel.org/r/20210125013255.25799-9-jee.heng.sia@intel.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>