CONFIG_ARCH_NETX is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Hilscher NetX based

configname: CONFIG_ARCH_NETX

ARM system type
└─>Hilscher NetX based
In linux kernel since version 2.6.18 (release Date: 2006-09-19)  
This enables support for systems based on the Hilscher NetX Soc