CONFIG_OMAP_OSK_MISTRAL is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_OMAP_OSK_MISTRAL.
Result is shown for kernelversion 6.7.7

Mistral QVGA board Support

configname: CONFIG_OMAP_OSK_MISTRAL

Linux Kernel Configuration
└─>TI OMAP1 specific features
└─>Mistral QVGA board Support
In linux kernel since version 2.6.14 (release Date: 2005-10-27)  
The OSK supports an optional add-on board with a Quarter-VGA
touchscreen, PDA-ish buttons, a resume button, bicolor LED,
and camera connector. Say Y here if you have this board.