usb: renesas_usbhs: Add device tree support for R-Car H2 and M2

This driver supports other SoCs, but they need boards/Soc depend code.
So, this patch adds device tree support for R-Car H2 and M2 initially.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>