CONFIG_ARCH_NETX is not available for the default architecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_ARCH_NETX.
Result is shown for kernelversion 5.9.9

Hilscher NetX based

configname: CONFIG_ARCH_NETX

ARM system type
└─> Hilscher NetX based

This enables support for systems based on the Hilscher NetX Soc