DMA transfer to/from SRC

     DMA      DMApp
[MEM] -> [SRC] -> [SSIU] -> [SSI]

     DMA      DMApp
[MEM] <- [SRC] <- [SSIU] <- [SSI]

Current sound driver is supporting
SSI/SRC random connection.
So, this patch is tring
SSI0 -> SRC2
SSI1 <- SRC3
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>