CONFIG_PTE_64BIT is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc

CONFIG_PTE_64BIT (not configurable)

configname: CONFIG_PTE_64BIT

Linux Kernel Configuration
└─>Processor support
└─>PTE_64BIT
In linux kernel since version 2.6.15 (release Date: 2006-01-02)  

is selected by
CONFIG_KVM_BOOK3S_32