CONFIG_E500 is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc

Freescale e500

modulename: idle_e500.ko

and/or

configname: CONFIG_E500

Processor Type
└─>Freescale e500
In linux kernel since version 2.6.15 (release Date: 2006-01-02)  

is selected by
CONFIG_PHYS_64BIT

is depended by
CONFIG_CORENET_GENERIC