dmaengine: dw: provide DMA capabilities

The new DMAEngine requirement is to provide what the DMA controller can do,
such as directions, bus widths, and residue granularity. The patch sets those
properties for the DesignWare DMA controller driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>