mx23_olinuxino: enable device tree

Add the dts file for the Olimex Olinuxino from the linux kernel, and enable
its use in this machine's defconfig.

Signed-off-by: Trevor Woerner <twoerner@gmail.com>
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index d994ac8..4df1f03 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -653,6 +653,9 @@
 dtb-$(CONFIG_MX23) += \
 	imx23-evk.dtb
 
+dtb-$(CONFIG_TARGET_MX23_OLINUXINO) += \
+	imx23-olinuxino.dtb
+
 dtb-$(CONFIG_MX28) += \
 	imx28-xea.dtb