default or selected kernelversion does not have config value CONFIG_IRDA_CACHE_LAST_LSAP.
Result is shown for kernelversion 6.7-rc3

Cache last LSAP

configname: CONFIG_IRDA_CACHE_LAST_LSAP

Linux Kernel Configuration
└─>Device Drivers
└─>Staging drivers
└─>IrDA (infrared) subsystem support
└─>Cache last LSAP
In linux kernel since version 2.6.12  
Say Y here if you want IrLMP to cache the last LSAP used. This
makes sense since most frames will be sent/received on the same
connection. Enabling this option will save a hash-lookup per frame.

If unsure, say Y.