CONFIG_ETRAX_DRAM_SIZE is not available for thedefaultarchitecture x86.
Result is shown for architecture cris
default or selected kernelversion does not have config value CONFIG_ETRAX_DRAM_SIZE.
Result is shown for kernelversion 6.7-rc3

DRAM size (dec, in MB)

configname: CONFIG_ETRAX_DRAM_SIZE

Linux Kernel Configuration
└─>Hardware setup
└─>DRAM size (dec, in MB)
In linux kernel since version 2.6.12  
Size of DRAM (decimal in MB) typically 2, 8 or 16.