kernelconfig_penguin
CONFIG_CPU_CP15_MMU is not available for the default architecture x86.
Result is shown for architecture arm
selects
CONFIG_CPU_CP15

is depended by
CONFIG_CPU_ARM1020E

CONFIG_CPU_CP15_MMU (not configurable)

configname: CONFIG_CPU_CP15_MMU

Linux Kernel Configuration
└─> CPU_CP15_MMU

Processor has the CP15 register, which has MMU related registers.