beaglebone: add DT for BeagleBone Black

The devicetree data for BeagleBone Black is the am335x–boneblack.dts file
(includes "am33xx.dtsi" and "am335x-bone-common.dtsi")

BeagleBone White uses the am335x-bone.dts file.

Signed-off-by: Marcelo Gutiérrez <kuyurix@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

configs/beaglebone_defconfig

@@ -36,4 +36,4 @@ BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="board/beaglebone/linux-3.12.config"
 BR2_LINUX_KERNEL_ZIMAGE=y
 BR2_LINUX_KERNEL_DTS_SUPPORT=y
-BR2_LINUX_KERNEL_INTREE_DTS_NAME="am335x-bone"
+BR2_LINUX_KERNEL_INTREE_DTS_NAME="am335x-bone am335x-boneblack"