arm: davinci: Migrate da850-evm to OF_UPSTREAM

The da850-evm can remove the U-Boot device trees if migrated
to OF_UPSTREAM.  This means pointing the device trees to the
ti/davinci directory.

Signed-off-by: Adam Ford <aford173@gmail.com>

v2:  Remove DTS from Makefile.
diff --git a/arch/arm/mach-davinci/Kconfig b/arch/arm/mach-davinci/Kconfig
index 25c5db4..8fa2660 100644
--- a/arch/arm/mach-davinci/Kconfig
+++ b/arch/arm/mach-davinci/Kconfig
@@ -9,6 +9,7 @@
 	select MACH_DAVINCI_DA850_EVM
 	select SOC_DA850
 	select SUPPORT_SPL
+	imply OF_UPSTREAM
 
 config TARGET_OMAPL138_LCDK
 	bool "OMAPL138 LCDK"