CONFIG_CPLB_SWITCH_TAB_L1 is not available for thedefaultarchitecture x86.
Result is shown for architecture blackfin
default or selected kernelversion does not have config value CONFIG_CPLB_SWITCH_TAB_L1.
Result is shown for kernelversion 6.7-rc3

Locate CPLB Switch Tables L1 Data Memory

configname: CONFIG_CPLB_SWITCH_TAB_L1

Linux Kernel Configuration
└─>Blackfin Processor Options
└─>Blackfin Kernel Optimizations
└─>Locate CPLB Switch Tables L1 Data Memory
In linux kernel since version 2.6.24 (release Date: 2008-01-24)  
If enabled, the CPLB Switch Tables are linked
into L1 data memory. (less latency)

depends
NOT CONFIG_BF531
NOT CONFIG_SMP