phy: rcar-gen3-usb2: Add support for r8a77965

This patch adds support for r8a77965 (R-Car M3-N). This SoC has
dedicated pins.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>