default or selected kernelversion does not have config value CONFIG_OPTEE_SHM_NUM_PRIV_PAGES.
Result is shown for kernelversion 6.9.5

Private Shared Memory Pages


Linux Kernel Configuration
└─>Device Drivers
└─>TEE drivers
└─>Private Shared Memory Pages
In linux kernel since version 4.2 (release Date: 2015-08-30)  
This sets the number of private shared memory pages to be
used by OP-TEE TEE driver.