DMA controller present on S700 SoC is compatible with the one on S900
(as most of registers are same), but it has different DMA descriptor
structure where registers "fcnt" and "ctrlb" uses different encoding.

For instance, on S900 "fcnt" starts at offset 0x0c and uses upper 12
bits whereas on S700, it starts at offset 0x1c and uses lower 12 bits.

This commit adds support for DMA controller present on S700.
Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com>
Link: https://lore.kernel.org/r/1595180527-11320-4-git-send-email-amittomer25@gmail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>