avr32: Use correct config symbol in atstk1004 board code

CONFIG_BOARD_ATSTK1002_SW2_CUSTOM should be
CONFIG_BOARD_ATSTK100X_SW2_CUSTOM.

Spotted by Robert P. J. Day.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>

arch/avr32/boards/atstk1000/atstk1004.c

@@ -129,7 +129,7 @@ static int __init atstk1004_init(void)
 #ifdef CONFIG_BOARD_ATSTK100X_SPI1
 	at32_add_device_spi(1, spi1_board_info, ARRAY_SIZE(spi1_board_info));
 #endif
-#ifndef CONFIG_BOARD_ATSTK1002_SW2_CUSTOM
+#ifndef CONFIG_BOARD_ATSTK100X_SW2_CUSTOM
 	at32_add_device_mci(0);
 #endif
 	at32_add_device_lcdc(0, &atstk1000_lcdc_data,