dmaengine: sh: Add Support SuperH DMA Engine driver

This supported all DMA channels, and it was tested in SH7722,
SH7780, SH7785 and SH7763.
This can not use with SH DMA API.

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
Reviewed-by: Matt Fleming <matt@console-pimps.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>