CONFIG_HAVE_AT91_DATAFLASH_CARD is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

CONFIG_HAVE_AT91_DATAFLASH_CARD (not configurable)

configname: CONFIG_HAVE_AT91_DATAFLASH_CARD

Linux Kernel Configuration
└─>Atmel Non-DT world
└─>HAVE_AT91_DATAFLASH_CARD
In linux kernel since version 2.6.33 (release Date: 2010-02-24)  
is depended by
CONFIG_MACH_AT91RM9200EK