CONFIG_MACH_GATEWAY7001 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Gateway 7001

modulename: gateway7001-setup.ko

configname: CONFIG_MACH_GATEWAY7001

Linux Kernel Configuration
└─>Intel IXP4xx Implementation Options
└─>Gateway 7001
In linux kernel since version 2.6.23 (release Date: 2007-10-09)  
Say 'Y' here if you want your kernel to support Gateway's
7001 Access Point. For more information on this platform,
see http://openwrt.org

source code:
selects
CONFIG_PCI