usb: phy: Fix USB_ULPI_VIEWPORT Kconfig dependency

USB_ULPI_VIEWPORT didn't depend on USB_ULPI, while USB_ULPI
is using non user selectable USB_ULPI_VIEWPORT. Fix this.
Signed-off-by: Ivan T. Ivanov <ivan.ivanov@linaro.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/phy/Kconfig

@@ -202,13 +202,13 @@ config USB_RCAR_GEN2_PHY
 config USB_ULPI
 	bool "Generic ULPI Transceiver Driver"
 	depends on ARM || ARM64
+	select USB_ULPI_VIEWPORT
 	help
 	  Enable this to support ULPI connected USB OTG transceivers which
 	  are likely found on embedded boards.
 
 config USB_ULPI_VIEWPORT
 	bool
-	depends on USB_ULPI
 	help
 	  Provides read/write operations to the ULPI phy register set for
 	  controllers with a viewport register (e.g. Chipidea/ARC controllers).