CONFIG_8xx_GPIO is not available for the default architecture x86.
Result is shown for architecture powerpc

GPIO API Support

configname: CONFIG_8xx_GPIO

Linux Kernel Configuration
└─> MPC8xx CPM Options
└─> GPIO API Support

In linux kernel since version 2.6.27 (release Date: 2008-10-09)  

Saying Y here will cause the ports on an MPC8xx processor to be used
with the GPIO API. If you say N here, the kernel needs less memory.

If in doubt, say Y here.