CONFIG_ARCH_IOP3XX is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

IOP3xx-based

configname: CONFIG_ARCH_IOP3XX

ARM system type
└─>IOP3xx-based
In linux kernel since version 2.6.12  
Support for Intel's IOP3XX (XScale) family of processors.

selects
CONFIG_PCI

depends
CONFIG_MMU

is selected by
CONFIG_ARCH_IQ31244