usb: xhci: Convert CONFIG_USB_XHCI_PCI to Kconfig

Add CONFIG_USB_XHCI_PCI as a Kconfig option.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>
Tested-by: Stefan Roese <sr@denx.de>
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index bc2c1f1..9edc589 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -31,6 +31,12 @@
 	  SoCs, which includes Armada8K, Armada3700 and other Armada
 	  family SoCs.
 
+config USB_XHCI_PCI
+	bool "Support for PCI-based xHCI USB controller"
+	default y if X86
+	help
+	  Enables support for the PCI-based xHCI controller.
+
 config USB_XHCI_ROCKCHIP
 	bool "Support for Rockchip on-chip xHCI USB controller"
 	depends on ARCH_ROCKCHIP