CONFIG_EXCEPTION_L1_SCRATCH is not available for thedefaultarchitecture x86.
Result is shown for architecture blackfin
default or selected kernelversion does not have config value CONFIG_EXCEPTION_L1_SCRATCH.
Result is shown for kernelversion 6.7-rc3

Locate exception stack in L1 Scratch Memory


Linux Kernel Configuration
└─>Blackfin Processor Options
└─>Blackfin Kernel Optimizations
└─>Locate exception stack in L1 Scratch Memory
In linux kernel since version 2.6.29 (release Date: 2009-03-23)  
Whenever an exception occurs, use the L1 Scratch memory for
stack storage. You cannot place the stacks of FLAT binaries
in L1 when using this option.

If you don't use L1 Scratch, then you should say Y here.