CONFIG_ARCH_SPEAR6XX is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

ST SPEAr6XX

modulename: spear6xx_clock.ko

and/or

spear6xx.ko

and/or

pl080.ko

configname: CONFIG_ARCH_SPEAR6XX

Linux Kernel Configuration
└─>ST SPEAr Family
└─>ST SPEAr6XX
In linux kernel since version 2.6.35 (release Date: 2010-08-01)  
Supports for ARM's SPEAR6XX family

source code:
/arch/arm/mach-spear/spear6xx.c


is selected by
CONFIG_DEBUG_SPEAR3XX