drivers: usb: Add USB_XHCI_ZYNQMP to Kconfig

Move symbol to Kconfig to cleanup configuration file.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index b9c5fbe..5129a57 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -37,6 +37,12 @@
 	help
 	  Enables support for the on-chip xHCI controller on Rockchip SoCs.
 
+config USB_XHCI_ZYNQMP
+	bool "Support for Xilinx ZynqMP on-chip xHCI USB controller"
+	depends on ARCH_ZYNQMP
+	help
+	  Enables support for the on-chip xHCI controller on Xilinx ZynqMP SoCs.
+
 endif # USB_XHCI_HCD
 
 config USB_EHCI_HCD