ARC: add support for reserved memory defined by device tree

Enable reserved memory initialization from device tree.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/Kconfig

@@ -35,6 +35,7 @@ config ARC
 	select NO_BOOTMEM
 	select OF
 	select OF_EARLY_FLATTREE
+	select OF_RESERVED_MEM
 	select PERF_USE_VMALLOC
 	select HAVE_DEBUG_STACKOVERFLOW
 	select HAVE_GENERIC_DMA_COHERENT

arch/arc/mm/init.c

@@ -13,6 +13,7 @@
 #ifdef CONFIG_BLK_DEV_INITRD
 #include <linux/initrd.h>
 #endif
+#include <linux/of_fdt.h>
 #include <linux/swap.h>
 #include <linux/module.h>
 #include <linux/highmem.h>
@@ -136,6 +137,9 @@ void __init setup_arch_memory(void)
 		memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
 #endif
 
+	early_init_fdt_reserve_self();
+	early_init_fdt_scan_reserved_mem();
+
 	memblock_dump_all();
 
 	/*----------------- node/zones setup --------------------------*/