CONFIG_SYS_SUPPORTS_RELOCATABLE is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

CONFIG_SYS_SUPPORTS_RELOCATABLE (not configurable)

configname: CONFIG_SYS_SUPPORTS_RELOCATABLE

Linux Kernel Configuration
└─>SYS_SUPPORTS_RELOCATABLE
In linux kernel since version 4.1 (release Date: 2015-06-21)  
Selected if the platform supports relocating the kernel.
The platform must provide plat_get_fdt() if it selects CONFIG_USE_OF
to allow access to command line and entropy sources.