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>

arch/arm/Kconfig

@@ -1918,6 +1918,7 @@ config USE_OF
 	select IRQ_DOMAIN
 	select OF
 	select OF_EARLY_FLATTREE
+	select OF_RESERVED_MEM
 	help
 	  Include support for flattened device tree machine descriptions.
 

arch/arm/mm/init.c

@@ -323,6 +323,8 @@ void __init arm_memblock_init(struct meminfo *mi,
 	if (mdesc->reserve)
 		mdesc->reserve();
 
+	early_init_fdt_scan_reserved_mem();
+
 	/*
 	 * reserve memory for DMA contigouos allocations,
 	 * must come from DMA area inside low memory