ARM: uniphier: enable DWC3 xHCI driver really

I thought commit d37d3184 ("ARM: uniphier: enable DWC3 xHCI
driver") enabled CONFIG_USB_DWC3_UNIPHIER, but CONFIG_USB_XHCI_DWC3
was missing in uniphier_v7_defconfig.  Re-add.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

configs/uniphier_v7_defconfig

@@ -49,7 +49,9 @@ CONFIG_SMC911X_BASE=0x0
 CONFIG_SMC911X_32_BIT=y
 CONFIG_USB=y
 CONFIG_USB_XHCI_HCD=y
+CONFIG_USB_XHCI_DWC3=y
 CONFIG_USB_EHCI_HCD=y
 CONFIG_USB_EHCI_GENERIC=y
 CONFIG_USB_DWC3=y
+CONFIG_USB_DWC3_UNIPHIER=y
 CONFIG_USB_STORAGE=y