arm: add support for reserved memory defined by device tree

Enable reserved memory initialization from device tree.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index e254198..d0262be 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1918,6 +1918,7 @@
 	select IRQ_DOMAIN
 	select OF
 	select OF_EARLY_FLATTREE
+	select OF_RESERVED_MEM
 	help
 	  Include support for flattened device tree machine descriptions.