CONFIG_SOC_IMX53 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

i.MX53 support

modulename: suspend-imx53.ko

and/or

mach-imx53.ko

configname: CONFIG_SOC_IMX53

Linux Kernel Configuration
└─>Freescale i.MX family
└─>i.MX53 support
In linux kernel since version 2.6.38 (release Date: 2011-03-14)  
This enables support for Freescale i.MX53 processor.

source code:
/arch/arm/mach-imx/