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

Arcom/Eurotech Vulcan

modulename: vulcan-setup.ko

configname: CONFIG_MACH_ARCOM_VULCAN

Linux Kernel Configuration
└─>Intel IXP4xx Implementation Options
└─>Arcom/Eurotech Vulcan
In linux kernel since version 2.6.36 (release Date: 2010-10-20)  
Say 'Y' here if you want your kernel to support Arcom's
Vulcan board.

source code:
arch/arm/mach-ixp4xx/vulcan-setup.c
selects
CONFIG_PCI