MLK-11344-7: dma: imx-sdma: Add hdmi audio support in sdma

MLK-11344-7: dma: imx-sdma: Add hdmi audio support in sdma

cherry-pick below patch from v3.14.y:
ENGR00329948-3: dma: imx-sdma: Add hdmi audio support
 in sdma

There's a missing script for hdmi audio support in current sdma driver,
thus add it.

This HDMI script doesn't use bd to copy memory like a normal one does
but only to update the memory address for HDMI internal AHB DMA and
then trigger its procedure automatically.

Signed-off-by: Shengjiu Wang <shengjiu.wang@freescale.com>
Signed-off-by: Robin Gong <b38343@freescale.com>
(cherry picked from commit dafddac916a03ae4477e2de7c1b7ad291f956f68)