CONFIG_SOC_LAN966 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
ARMv7 based Microchip LAN966 SoC family
configname: CONFIG_SOC_LAN966
Linux Kernel Configuration
└─>AT91/Microchip SoCs
└─>ARMv7 based Microchip LAN966 SoC family
In linux kernel since version 5.2 (release Date: 2019-07-07)
This enables support for ARMv7 based Microchip LAN966 SoC family.