dmaengine: dw-axi-dmac: Add device_synchronize() callback

Add support for device_synchronize() callback function to sync with
dmaengine_terminate_sync().

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/20210125013255.25799-5-jee.heng.sia@intel.com


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