CONFIG_REDWOOD_5 is not available for thedefaultarchitecture x86.
Result is shown for architecture ppc

Redwood-5

modulename: redwood5.ko

and/or

ibmstb4.ko

configname: CONFIG_REDWOOD_5

Machine Type
└─>Redwood-5
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
This option enables support for the IBM STB04 evaluation board.

source code:
arch/ppc/platforms/4xx/redwood5.c
is selected by
CONFIG_SMC91X