CONFIG_ARCH_KEYSTONE is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
Texas Instruments Keystone Devices
configname: CONFIG_ARCH_KEYSTONE
Linux Kernel Configuration
└─>Texas Instruments Keystone Devices
In linux kernel since version 3.10 (release Date: 2013-06-30)
Support for boards based on the Texas Instruments Keystone family of
SoCs.
SoCs.
selects
CONFIG_CPU_V7CONFIG_ARM_GIC
CONFIG_HAVE_ARM_ARCH_TIMER
CONFIG_HAVE_SMP
CONFIG_CLKSRC_MMIO
CONFIG_GENERIC_CLOCKEVENTS
CONFIG_ARCH_WANT_OPTIONAL_GPIOLIB
CONFIG_ARM_ERRATA_798181