reset: rzg2l-usbphy-ctrl: Add suspend/resume support

reset: rzg2l-usbphy-ctrl: Add suspend/resume support

The RZ/G2L USBPHY control driver is also used on the RZ/G3S SoC.
The RZ/G3S SoC supports a power-saving mode in which power to most USB
components (including the USBPHY control block) is turned off. Because of
this, the USBPHY control block needs to be reconfigured when returning
from power-saving mode.

Add suspend/resume support to handle runtime suspend/resume of the device,
assert/deassert the reset signal, and reinitialize the USBPHY control
block.

Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>