CONFIG_ARCH_IOP3XX is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_ARCH_IOP3XX.
Result is shown for kernelversion 5.4.123

IOP3xx-based

configname: CONFIG_ARCH_IOP3XX

ARM system type
└─>IOP3xx-based
In linux kernel since version 2.6.12  
selects
CONFIG_PCI

is selected by
CONFIG_ARCH_IQ31244