CONFIG_LAZY_SAVE_FPU is not available for thedefaultarchitecture x86.
Result is shown for architecture mn10300
default or selected kernelversion does not have config value CONFIG_LAZY_SAVE_FPU.
Result is shown for kernelversion 6.7-rc3

Save FPU state lazily


Linux Kernel Configuration
└─>Panasonic MN10300 system setup
└─>Save FPU state lazily
In linux kernel since version 2.6.37 (release Date: 2011-01-04)  
Enable this to be lazy in the saving of the FPU state to the owning
task's thread struct. This is useful if most tasks on the system
don't use the FPU as only those tasks that use it will pass it
between them, and the state needn't be saved for a task that isn't
using it.

This can't be so easily used on SMP as the process that owns the FPU
state on a CPU may be currently running on another CPU, so for the
moment, it is disabled.