CONFIG_MACH_BALLOON3 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Balloon 3 board

modulename: pxa2xx_balloon3.ko

and/or

balloon3.ko

configname: CONFIG_MACH_BALLOON3

Linux Kernel Configuration
└─>Intel PXA2xx/PXA3xx Implementations
└─>Balloon 3 board
In linux kernel since version 2.6.32 (release Date: 2009-12-02)  
source code:
arch/arm/mach-pxa/balloon3.c

depends
CONFIG_ARCH_PXA |
| CONFIG_ATAGS or CONFIG_UNUSED_BOARD_FILES

is selected by
CONFIG_PCMCIA_PXA2XX