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

CONFIG_PTE_64BIT (not configurable)

configname: CONFIG_PTE_64BIT

Linux/PowerPC Kernel Configuration
└─>Processor
└─>PTE_64BIT
In linux kernel since version 2.6.15 (release Date: 2006-01-02)  
depends
CONFIG_44x or CONFIG_E500