CONFIG_TICKSOURCE_GPTMR0 is not available for thedefaultarchitecture x86.
Result is shown for architecture blackfin

Gptimer0 (SCLK domain)

configname: CONFIG_TICKSOURCE_GPTMR0

Kernel Tick Source
└─>Gptimer0 (SCLK domain)
In linux kernel since version 2.6.31 (release Date: 2009-09-09)