This patch expands USB-DMAC channels for R-Car Gen2 SoCs. The SoCs
have 4 channels. If d{2,3}_{t,x}x_id are not set, this driver never
uses the expanded USB-DMAC channels.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>