imx6: aristainetos: readd aristainetos 2b board

readd aristainetos 2b board.

Signed-off-by: Heiko Schocher <hs@denx.de>
diff --git a/board/aristainetos/common/Kconfig b/board/aristainetos/common/Kconfig
index 8f25614..a15993e 100644
--- a/board/aristainetos/common/Kconfig
+++ b/board/aristainetos/common/Kconfig
@@ -3,6 +3,7 @@
 	help
 	  version of aristainetos board version
 	  2 version 2
+	  3 version 2b
 
 config SYS_I2C_MXC_I2C1
 	default y