CONFIG_IXP4XX_PCI_LEGACY is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
IXP4xx legacy PCI driver support
configname: CONFIG_IXP4XX_PCI_LEGACY
Linux Kernel Configuration
└─>Intel IXP4xx Implementation Options
└─>IXP4xx legacy PCI driver support
In linux kernel since version 5.14 (release Date: 2021-08-29)
Selects legacy PCI driver.
Not recommended for new development.
Not recommended for new development.