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

CONFIG_PPC_DCR_MMIO (not configurable)

configname: CONFIG_PPC_DCR_MMIO

Linux/PowerPC Kernel Configuration
└─>PPC_DCR_MMIO
In linux kernel since version 2.6.20 (release Date: 2007-02-04)