dw_dmac: use 'u32' for LLI structure members, not dma_addr_t

Use 'u32' for the LLI structure members, which are defined by hardware to be
32-bit. dma_addr_t is much more vague about its actual size.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>