CONFIG_MPC836x_MDS is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc
default or selected kernelversion does not have config value CONFIG_MPC836x_MDS.
Result is shown for kernelversion 6.9.9

Freescale MPC836x MDS

modulename: mpc836x_mds.ko

configname: CONFIG_MPC836x_MDS

Linux Kernel Configuration
└─>83xx-based boards
└─>Freescale MPC836x MDS
In linux kernel since version 2.6.21 (release Date: 2007-04-25)  
This option enables support for the MPC836x MDS Processor Board.

source code: