am33xx/omap: Enable CONFIG_OF_CONTROL

Add support for device tree control and add device tree files for the
beaglebone black initially.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index 5554615..61527a2 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -31,6 +31,7 @@
 	zynq-zc770-xm010.dtb \
 	zynq-zc770-xm012.dtb \
 	zynq-zc770-xm013.dtb
+dtb-$(CONFIG_AM33XX) += am335x-boneblack.dtb
 
 targets += $(dtb-y)