CONFIG_ARCH_IOP32X is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

IOP32x-based

configname: CONFIG_ARCH_IOP32X

ARM system type
└─>IOP32x-based
In linux kernel since version 2.6.19 (release Date: 2006-11-29)  
Support for Intel's 80219 and IOP32X (XScale) family of
processors.