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/configs/xilinx_zynqmp_zc1751_xm015_dc1_defconfig b/configs/xilinx_zynqmp_zc1751_xm015_dc1_defconfig
index 9da0306..41fcc8d 100644
--- a/configs/xilinx_zynqmp_zc1751_xm015_dc1_defconfig
+++ b/configs/xilinx_zynqmp_zc1751_xm015_dc1_defconfig
@@ -58,6 +58,7 @@
 CONFIG_USB=y
 CONFIG_USB_XHCI_HCD=y
 CONFIG_USB_XHCI_DWC3=y
+CONFIG_USB_XHCI_ZYNQMP=y
 CONFIG_USB_DWC3=y
 CONFIG_USB_DWC3_GADGET=y
 CONFIG_USB_ULPI_VIEWPORT=y