CONFIG_ARCH_MICROCHIP is not available for thedefaultarchitecture x86.
Result is shown for architecture riscv
default or selected kernelversion does not have config value CONFIG_ARCH_MICROCHIP.
Result is shown for kernelversion 6.9.8

Microchip SoCs

configname: CONFIG_ARCH_MICROCHIP

Linux Kernel Configuration
└─>SoC selection
└─>Microchip SoCs
In linux kernel since version 4.19.318 (release Date: 2024-07-18)  
This enables support for Microchip SoC platforms.