CONFIG_SCB4_MI0_SLOT15 is not available for thedefaultarchitecture x86.
Result is shown for architecture blackfin
default or selected kernelversion does not have config value CONFIG_SCB4_MI0_SLOT15.
Result is shown for kernelversion 6.7-rc3

Slot 15 slave interface id

configname: CONFIG_SCB4_MI0_SLOT15

Linux Kernel Configuration
└─>BF609 Specific Configuration
└─>SCB4 Master Interface 0
└─>Slot 15 slave interface id
In linux kernel since version 3.12 (release Date: 2013-11-03)