imx6: aristainetos: add version variable

add VERSION_VARIABLE

Signed-off-by: Heiko Schocher <hs@denx.de>
diff --git a/configs/aristainetos2_defconfig b/configs/aristainetos2_defconfig
index dfaaf5d..d2411c6 100644
--- a/configs/aristainetos2_defconfig
+++ b/configs/aristainetos2_defconfig
@@ -14,6 +14,7 @@
 # CONFIG_CONSOLE_MUX is not set
 CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 CONFIG_SUPPORT_RAW_INITRD=y
+CONFIG_VERSION_VARIABLE=y
 CONFIG_BOUNCE_BUFFER=y
 CONFIG_BOARD_TYPES=y
 CONFIG_BOARD_EARLY_INIT_F=y