CONFIG_USB_XHCI_PCI (not configurable)

modulename: xhci-pci.ko

configname: CONFIG_USB_XHCI_PCI

Linux Kernel Configuration
└─>Device Drivers
└─>USB support
└─>USB_XHCI_PCI
In linux kernel since version 3.18 (release Date: 2014-12-07)  
source code:
drivers/usb/host/xhci-pci.c