arm, am335x: siemens: enable DM/DTS support

enable basic DM/DTS support for the siemens am335x based boards.

Signed-off-by: Heiko Schocher <hs@denx.de>
diff --git a/configs/thuban_defconfig b/configs/thuban_defconfig
index 0b69c07..5fcffa2 100644
--- a/configs/thuban_defconfig
+++ b/configs/thuban_defconfig
@@ -1,5 +1,8 @@
 CONFIG_ARM=y
 CONFIG_TARGET_THUBAN=y
+CONFIG_SYS_MALLOC_F_LEN=0x2000
+CONFIG_DM_SERIAL=y
+CONFIG_DEFAULT_DEVICE_TREE="am335x-draco"
 CONFIG_SPL=y
 CONFIG_BOOTDELAY=3
 CONFIG_HUSH_PARSER=y
@@ -23,6 +26,9 @@
 CONFIG_CMD_CACHE=y
 CONFIG_CMD_TIME=y
 CONFIG_CMD_EXT2=y
+CONFIG_OF_CONTROL=y
+CONFIG_OF_EMBED=y
+CONFIG_DM=y
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_WINBOND=y
 CONFIG_SYS_NS16550=y