CONFIG_P2040_RDB is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc

Freescale P2040 RDB

modulename: p2040_rdb.ko

configname: CONFIG_P2040_RDB

Linux Kernel Configuration
└─>Freescale Book-E Machine Type
└─>Freescale P2040 RDB
In linux kernel since version 3.1 (release Date: 2011-10-24)  
This option enables support for the P2040 RDB board

source code: