CONFIG_KERNEL_BASE_ADDR is not available for thedefaultarchitecture x86.
Result is shown for architecture microblaze

Physical address where Linux Kernel is

configname: CONFIG_KERNEL_BASE_ADDR

Linux Kernel Configuration
└─>Platform options
└─>Physical address where Linux Kernel is
In linux kernel since version 2.6.30 (release Date: 2009-06-09)  
BASE Address for kernel