arm: am335x-pdu001: Move from embedded to separate DTB

There is no need for an embedded device tree for this board so let the
build process generate a separate u-boot.dtb file instead.
Signed-off-by: NFelix Brack <fb@ltec.ch>

arch/arm/mach-omap2/am33xx/Kconfig

@@ -206,6 +206,7 @@ config TARGET_PDU001
 	bool "Support PDU001"
 	select DM
 	select DM_SERIAL
+	imply SPL_SEPARATE_BSS
 	imply CMD_DM
 	help
 	  Support for PDU001 platform developed by EETS GmbH.

configs/am335x_pdu001_defconfig

@@ -32,7 +32,7 @@ CONFIG_CMD_PMIC=y
 CONFIG_CMD_REGULATOR=y
 CONFIG_OF_CONTROL=y
 CONFIG_SPL_OF_CONTROL=y
-CONFIG_OF_EMBED=y
+CONFIG_OF_SEPARATE=y
 CONFIG_DEFAULT_DEVICE_TREE="am335x-pdu001"
 # CONFIG_NET is not set
 CONFIG_SPL_DM=y