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

Arcom/Eurotech VIPER SBC

modulename: viper.ko

configname: CONFIG_ARCH_VIPER

Linux Kernel Configuration
└─>Intel PXA2xx/PXA3xx Implementations
└─>Arcom/Eurotech VIPER SBC
In linux kernel since version 2.6.28 (release Date: 2008-12-24)  
source code:
arch/arm/mach-pxa/viper.c

depends
CONFIG_ARCH_PXA