default or selected kernelversion does not have config value CONFIG_USB_USBNET_MII.
Result is shown for kernelversion 5.15.113

CONFIG_USB_USBNET_MII (not configurable)

configname: CONFIG_USB_USBNET_MII

Linux Kernel Configuration
└─>Device Drivers
└─>USB support
└─>USB Network Adapters
└─>USB_USBNET_MII
In linux kernel since version 2.6.20 (release Date: 2007-02-04)