CONFIG_ARCH_OMAP1 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

TI OMAP1

configname: CONFIG_ARCH_OMAP1

OMAP System Type
└─>TI OMAP1
In linux kernel since version 2.6.13 (release Date: 2005-08-28)  
"Systems based on omap7xx, omap15xx or omap16xx"


depends
 or CONFIG_MMU or CONFIG_ATAGS |
| CONFIG_CPU_LITTLE_ENDIAN or CONFIG_ARCH_MULTI_V4T or CONFIG_ARCH_MULTI_V5