CONFIG_SOC_IMX6SX is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
i.MX6 SoloX support
modulename: clk-imx6sx.ko
configname: CONFIG_SOC_IMX6SX
Linux Kernel Configuration
└─>Freescale i.MX family
└─>i.MX6 SoloX support
In linux kernel since version 3.10 (release Date: 2013-06-30)
This enables support for Freescale i.MX6 SoloX processor.