phy: socionext: Add UniPhier USB3 PHY driver

Add USB3 PHY driver support to control clocks and resets needed to enable
PHY. The phy_ops->init() and exit() control PHY clocks and resets only,
and clocks and resets for the controller and the parent logic are enabled
in advance.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Reviewed-by: Marek Vasut <marex@denx.de>
diff --git a/drivers/phy/socionext/Kconfig b/drivers/phy/socionext/Kconfig
index bcd579e..de87d5b0 100644
--- a/drivers/phy/socionext/Kconfig
+++ b/drivers/phy/socionext/Kconfig
@@ -10,3 +10,11 @@
 	help
 	  Enable this to support PHY implemented in PCIe controller
 	  on UniPhier SoCs.
+
+config PHY_UNIPHIER_USB3
+	bool "UniPhier USB3 PHY driver"
+	depends on PHY && ARCH_UNIPHIER
+	imply REGMAP
+	help
+	  Enable this to support PHY implemented in USB3 controller
+	  on UniPhier SoCs.