CONFIG_ETRAX_SPI_GPIO is not available for thedefaultarchitecture x86.
Result is shown for architecture cris

Bitbanged SPI using gpio pins

configname: CONFIG_ETRAX_SPI_GPIO

Linux Kernel Configuration
└─>Bitbanged SPI using gpio pins
In linux kernel since version 2.6.25 (release Date: 2008-04-16)  
Say Y for an MMC/SD socket connected to general I/O pins (but not
a complete synchronous serial ports), or for devices using the SPI
protocol on general I/O pins. Slow and slows down the system.
Say m to build it as a module, which will be called spi_crisv32_gpio.
(You need to select MMC separately.)