fdt: Fixup only valid memory banks

Memory banks with address 0 and size 0 are empty and should not be
passed to the OS via device tree.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
diff --git a/common/fdt_support.c b/common/fdt_support.c
index 17623a1..bd0478d 100644
--- a/common/fdt_support.c
+++ b/common/fdt_support.c
@@ -418,7 +418,7 @@
 int fdt_fixup_memory_banks(void *blob, u64 start[], u64 size[], int banks)
 {
 	int err, nodeoffset;
-	int len;
+	int len, i;
 	u8 tmp[MEMORY_BANKS_MAX * 16]; /* Up to 64-bit address + 64-bit size */
 
 	if (banks > MEMORY_BANKS_MAX) {
@@ -450,6 +450,12 @@
 	if (!banks)
 		return 0;
 
+	for (i = 0; i < banks; i++)
+		if (start[i] == 0 && size[i] == 0)
+			break;
+
+	banks = i;
+
 	len = fdt_pack_reg(blob, tmp, start, size, banks);
 
 	err = fdt_setprop(blob, nodeoffset, "reg", tmp, len);