CONFIG_MIPS_CPS_NS16550 is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

CONFIG_MIPS_CPS_NS16550 (not configurable)

modulename: cps-vec-ns16550.ko

configname: CONFIG_MIPS_CPS_NS16550

Linux Kernel Configuration
└─>CPS SMP NS16550 UART output
└─>MIPS_CPS_NS16550
In linux kernel since version 4.1 (release Date: 2015-06-21)  
source code:
arch/mips/kernel/