usb: gadget: renesas_usb3: add support for Renesas USB3.0 peripheral controller

R-Car H3 has USB3.0 peripheral controllers. This controller's has the
following features:
 - Supports super, high and full speed
 - Contains 30 pipes for bulk or interrupt transfer
 - Contains dedicated DMA controller

This driver doesn't support the dedicated DMAC for now.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>