CONFIG_SCB3_MI0 is not available for thedefaultarchitecture x86.
Result is shown for architecture blackfin
default or selected kernelversion does not have config value CONFIG_SCB3_MI0.
Result is shown for kernelversion 6.7-rc3

SCB3 Master Interface 0

configname: CONFIG_SCB3_MI0

Linux Kernel Configuration
└─>BF609 Specific Configuration
└─>SCB3 Master Interface 0
In linux kernel since version 3.12 (release Date: 2013-11-03)  
The slave interface id of each slot should be set according following table.
LP0 -- 0
LP1 -- 1
LP2 -- 2
LP3 -- 3
UART0TX -- 4
UART0RX -- 5
UART1TX -- 4
UART1RX -- 5