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

TI OSK Support

modulename: board-osk.ko

configname: CONFIG_MACH_OMAP_OSK

Linux Kernel Configuration
└─>TI OMAP Implementations
└─>TI OSK Support
In linux kernel since version 2.6.12  
TI OMAP 5912 OSK (OMAP Starter Kit) board support. Say Y here
if you have such a board.

source code:
arch/arm/mach-omap/board-osk.c