CONFIG_MIPS_DISABLE_OBSOLETE_IDE is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

CONFIG_MIPS_DISABLE_OBSOLETE_IDE (not configurable)

configname: CONFIG_MIPS_DISABLE_OBSOLETE_IDE

Linux/MIPS Kernel Configuration
└─>MIPS_DISABLE_OBSOLETE_IDE
In linux kernel since version 2.6.12