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

CONFIG_MIPS_MSC (not configurable)

modulename: irq-msc01.ko

and/or

ops-msc.ko

configname: CONFIG_MIPS_MSC

Linux/MIPS Kernel Configuration
└─>Machine selection
└─>MIPS_MSC
In linux kernel since version 2.6.12  
source code:
arch/mips/pci/ops-msc.c