default or selected kernelversion does not have config value CONFIG_NET_MEDIATEK_SOC_STAGING.
Result is shown for kernelversion 6.9.9

MediaTek SoC Gigabit Ethernet support

modulename: mtk-eth-soc.ko

configname: CONFIG_NET_MEDIATEK_SOC_STAGING

Linux Kernel Configuration
└─>Device Drivers
└─>Staging drivers
└─>MediaTek SoC Gigabit Ethernet support
In linux kernel since version 4.2 (release Date: 2015-08-30)  
This driver supports the gigabit ethernet MACs in the
MediaTek SoC family.

source code: