phy: renesas: rcar-gen3-usb2: Add suspend/resume support

phy: renesas: rcar-gen3-usb2: Add suspend/resume support

The Renesas RZ/G3S supports a power saving mode where power to most of the
SoC components is turned off. The USB PHY is among these components.
Because of this the settings applied in driver probe need to be executed
also on resume path. On suspend path only reset signal need to be asserted.
Add suspend/resume support.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20251119120418.686224-3-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>