CONFIG_BFIN_KERNEL_CLOCK_MEMINIT_SPEC is not available for thedefaultarchitecture x86.
Result is shown for architecture blackfin

Provide accurate Timings based on target SCLK

configname: CONFIG_BFIN_KERNEL_CLOCK_MEMINIT_SPEC

DDR/SDRAM Timing
└─>Provide accurate Timings based on target SCLK
In linux kernel since version 2.6.29 (release Date: 2009-03-23)  
Please consult the Blackfin Hardware Reference Manuals as well
as the memory device datasheet.
http://docs.blackfin.uclinux.org/doku.php?id=bfin:sdram