usb: renesas_usbhs: add support for RZ/G2E

usb: renesas_usbhs: add support for RZ/G2E

HS-USB found in RZ/G2E (a.k.a. r8a774c0) is very similar to the
one found in R-Car E3 (a.k.a. r8a77990), as it needs to release
the PLL reset by the UGCTRL register like R-Car E3, therefore add
r8a774c0 support in a similar fashion to what was done for the
r8a77990.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>