MediaTek MT7621 PCI Controller

modulename: pci-mt7621.ko

and/or

configname: CONFIG_PCI_MT7621

Linux Kernel Configuration
└─>Device Drivers
└─>Staging drivers
└─>MediaTek MT7621 PCI Controller
In linux kernel since version 4.2 (release Date: 2015-08-30)  
This selects a driver for the MediaTek MT7621 PCI Controller.