default or selected kernelversion does not have config value CONFIG_ALIENWARE_WMI_LEGACY.
Result is shown for kernelversion 6.6.86

Alienware Legacy WMI device driver

configname: CONFIG_ALIENWARE_WMI_LEGACY

Linux Kernel Configuration
└─>Device Drivers
└─>X86 Platform Specific Device Drivers
└─>Dell X86 Platform Specific Device Drivers
└─>Alienware Legacy WMI device driver
In linux kernel since version 6.6.86 (release Date: 2025-04-07)  
Legacy Alienware WMI driver with AlienFX LED control capabilities.