CONFIG_SH_7710VOIPGW is not available for thedefaultarchitecture x86.
Result is shown for architecture sh

SH7710-VOIP-GW

configname: CONFIG_SH_7710VOIPGW

SuperH system type
└─>SH7710-VOIP-GW
In linux kernel since version 2.6.19 (release Date: 2006-11-29)  
Select this option to build a kernel for the SH7710 based
VOIP GW.