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

SPEAr6XX

modulename: spear6xx_clock.ko

and/or

spear6xx.ko

and/or

pl080.ko

configname: CONFIG_ARCH_SPEAR6XX

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

source code:
arch/arm/plat-spear/pl080.c

depends
 or CONFIG_ARCH_MULTI_V5 |
| CONFIG_PLAT_SPEAR or  NOT CONFIG_ARCH_SPEAR13XX

is selected by
CONFIG_MACH_SPEAR600