CONFIG_PLAT_SPEAR is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
ST SPEAr Family
configname: CONFIG_PLAT_SPEAR
Linux Kernel Configuration
└─>ST SPEAr Family
In linux kernel since version 2.6.35 (release Date: 2010-08-01)
selects
CONFIG_ARCH_REQUIRE_GPIOLIBCONFIG_ARM_AMBA
CONFIG_CLKDEV_LOOKUP
CONFIG_CLKSRC_MMIO
CONFIG_COMMON_CLK
CONFIG_GENERIC_CLOCKEVENTS
CONFIG_HAVE_CLK