CONFIG_MPC832x_RDB is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc

Freescale MPC832x RDB

modulename: mpc832x_rdb.ko

configname: CONFIG_MPC832x_RDB

Machine Type
└─>Freescale MPC832x RDB
In linux kernel since version 2.6.22 (release Date: 2007-07-08)  
This option enables support for the MPC8323 RDB board.

source code: