CONFIG_PPC_85xx is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc

Freescale 85xx

modulename: misc.ko

configname: CONFIG_PPC_85xx

Processor Type
└─>Freescale 85xx
In linux kernel since version 2.6.17 (release Date: 2006-06-17)  
source code:
/arch/powerpc/platforms/85xx/

is selected by
CONFIG_MPC85xx