dma: imx-sdma: Fix warnings for LPAE builds

This resolves a number of warnings such as the below when building with
64-bit dma_addr_t on arm:

drivers/dma/imx-sdma.c:1092:3: warning: format '%x' expects argument of
  type 'unsigned int', but argument 6 has type 'dma_addr_t' [-Wformat=]

..by upcasting to u64 and using %llx.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>