CONFIG_MPC837x_MDS is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc

Freescale MPC837x MDS

modulename: mpc837x_mds.ko

configname: CONFIG_MPC837x_MDS

Linux Kernel Configuration
└─>83xx Board Type
└─>Freescale MPC837x MDS
In linux kernel since version 2.6.25 (release Date: 2008-04-16)  
This option enables support for the MPC837x MDS Processor Board.

source code: