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

CONFIG_MSP_ETH (not configurable)

configname: CONFIG_MSP_ETH

Linux Kernel Configuration
└─>MSP_ETH
In linux kernel since version 2.6.39 (release Date: 2011-05-18)  

depends
CONFIG_PMC_MSP