CONFIG_MACH_MX51_BABBAGE is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
Support MX51 BABBAGE platforms
modulename: board-mx51_babbage.ko
configname: CONFIG_MACH_MX51_BABBAGE
Linux Kernel Configuration
└─>Support MX51 BABBAGE platforms
In linux kernel since version 2.6.34 (release Date: 2010-05-16)
Include support for MX51 Babbage platform, also known as MX51EVK in
u-boot. This includes specific configurations for the board and its
peripherals.
u-boot. This includes specific configurations for the board and its
peripherals.