imx6: aristainetos: disable gigabit support

gigabit support does not work on the aristainetos
board, so disable it.

Signed-off-by: Heiko Schocher <hs@denx.de>
diff --git a/include/configs/aristainetos-common.h b/include/configs/aristainetos-common.h
index ab14a1a..9a6c205 100644
--- a/include/configs/aristainetos-common.h
+++ b/include/configs/aristainetos-common.h
@@ -27,6 +27,7 @@
 #define CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
 
 #define CONFIG_EXTRA_ENV_SETTINGS \
+	"disable_giga=yes\0" \
 	"script=u-boot.scr\0" \
 	"fit_file=/boot/system.itb\0" \
 	"loadaddr=0x12000000\0" \