fix(zynqmp): fix DT reserved allocated size

BL31_LIMIT is not size but reserved node reg property contains base
address and size that's why BL31_LIMIT - BL31_BASE + 1 is correct size
of reseved space for BL31.
Also update warning message to cover that it is for BL31.

Change-Id: I53f53d2170eb873f758f9ba250d54f57f0b562b4
Signed-off-by: Michal Simek <michal.simek@amd.com>
diff --git a/plat/xilinx/zynqmp/bl31_zynqmp_setup.c b/plat/xilinx/zynqmp/bl31_zynqmp_setup.c
index 1d59537..36cf992 100644
--- a/plat/xilinx/zynqmp/bl31_zynqmp_setup.c
+++ b/plat/xilinx/zynqmp/bl31_zynqmp_setup.c
@@ -197,8 +197,9 @@
 	}
 
 	/* Reserve memory used by Trusted Firmware. */
-	if (fdt_add_reserved_memory(dtb, "tf-a", BL31_BASE, BL31_LIMIT - BL31_BASE)) {
-		WARN("Failed to add reserved memory nodes to DT.\n");
+	if (fdt_add_reserved_memory(dtb, "tf-a", BL31_BASE,
+				    BL31_LIMIT - BL31_BASE + 1)) {
+		WARN("Failed to add reserved memory nodes for BL31 to DT.\n");
 	}
 
 	ret = fdt_pack(dtb);