CONFIG_MACH_PCM043 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Support Phytec pcm043 (i.MX35) platforms

modulename: mach-pcm043.ko

configname: CONFIG_MACH_PCM043

Linux Kernel Configuration
└─>Freescale i.MX support
└─>Support Phytec pcm043 (i.MX35) platforms
In linux kernel since version 2.6.31 (release Date: 2009-09-09)  
Include support for Phytec pcm043 platform. This includes
specific configurations for the board and its peripherals.

source code:
arch/arm/mach-imx/mach-pcm043.c