CONFIG_ARCH_STM32 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
STMicrolectronics STM32
modulename: clk-stm32f4.ko
configname: CONFIG_ARCH_STM32
Linux Kernel Configuration
└─>STMicrolectronics STM32
In linux kernel since version 3.10 (release Date: 2013-06-30)
Support for STMicroelectronics STM32 processors.