CONFIG_MACH_MX27 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

i.MX27 support

modulename: cpu-imx27.ko

and/or

clock-imx27.ko

configname: CONFIG_MACH_MX27

CPUs:
└─>i.MX27 support
In linux kernel since version 2.6.27 (release Date: 2008-10-09)  
This enables support for Freescale's MX2 based i.MX27 processor.

source code:
/arch/arm/mach-imx/
is selected by
CONFIG_MACH_PCA100