CONFIG_ARCH_OMAP24XX is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

OMAP24xx Based System

configname: CONFIG_ARCH_OMAP24XX

Linux Kernel Configuration
└─>OMAP24xx Based System
In linux kernel since version 2.6.15 (release Date: 2006-01-02)  

is selected by
CONFIG_SPI_OMAP24XX