CONFIG_LINUX_RAM_BASE is not available for thedefaultarchitecture x86.
Result is shown for architecture arc

RAM base address


Linux Kernel Configuration
└─>ARC Architecture Configuration
└─>RAM base address
In linux kernel since version 4.2 (release Date: 2015-08-30)  
By default Linux is linked at base of RAM. However in some special
cases (such as HSDK), Linux can't be linked at start of DDR, hence
this option.