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

Generic OMAP board

modulename: board-generic.ko

configname: CONFIG_MACH_OMAP_GENERIC

Linux Kernel Configuration
└─>Generic OMAP board
In linux kernel since version 2.6.12  
source code:
arch/arm/mach-omap2/board-generic.c