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/arch/arm/Kconfig b/arch/arm/Kconfig
index 80a3f93..84cabb8 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -350,31 +350,49 @@
 	bool "Support draco"
 	select CPU_V7
 	select SUPPORT_SPL
+	select DM
+	select DM_SERIAL
+	select DM_GPIO
 
 config TARGET_THUBAN
 	bool "Support thuban"
 	select CPU_V7
 	select SUPPORT_SPL
+	select DM
+	select DM_SERIAL
+	select DM_GPIO
 
 config TARGET_RASTABAN
 	bool "Support rastaban"
 	select CPU_V7
 	select SUPPORT_SPL
+	select DM
+	select DM_SERIAL
+	select DM_GPIO
 
 config TARGET_ETAMIN
         bool "Support etamin"
         select CPU_V7
         select SUPPORT_SPL
+	select DM
+	select DM_SERIAL
+	select DM_GPIO
 
 config TARGET_PXM2
 	bool "Support pxm2"
 	select CPU_V7
 	select SUPPORT_SPL
+	select DM
+	select DM_SERIAL
+	select DM_GPIO
 
 config TARGET_RUT
 	bool "Support rut"
 	select CPU_V7
 	select SUPPORT_SPL
+	select DM
+	select DM_SERIAL
+	select DM_GPIO
 
 config TARGET_PENGWYN
 	bool "Support pengwyn"