MLK-16885-1: DMA: imx-sdma: update the buswidth that is supported

update buswidth that is supported by sdma.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com>
Signed-off-by: Srikanth Krishnakar <Srikanth_Krishnakar@mentor.com>