libfdt: return correct value if #size-cells property is not present

According to the device tree specification, the default value for
was not present.

This patch also makes fdt_address_cells() and fdt_size_cells() conform
to the behaviour documented in libfdt.h. The defaults are only returned
if fdt_getprop() returns -FDT_ERR_NOTFOUND, otherwise the actual error
is returned.

This is based on upstream commit:
aa7254d ("libfdt: return correct value if #size-cells property is not present")
but misses the test case part, as we don't implement them in U-Boot.

Signed-off-by: Matthias Brugger <mbrugger@suse.com>
diff --git a/scripts/dtc/libfdt/fdt_addresses.c b/scripts/dtc/libfdt/fdt_addresses.c
index 49537b5..f13a87d 100644
--- a/scripts/dtc/libfdt/fdt_addresses.c
+++ b/scripts/dtc/libfdt/fdt_addresses.c
@@ -64,7 +64,7 @@
 
 	c = fdt_getprop(fdt, nodeoffset, name, &len);
 	if (!c)
-		return 2;
+		return len;
 
 	if (len != sizeof(*c))
 		return -FDT_ERR_BADNCELLS;
@@ -78,10 +78,20 @@
 
 int fdt_address_cells(const void *fdt, int nodeoffset)
 {
-	return fdt_cells(fdt, nodeoffset, "#address-cells");
+	int val;
+
+	val = fdt_cells(fdt, nodeoffset, "#address-cells");
+	if (val == -FDT_ERR_NOTFOUND)
+		return 2;
+	return val;
 }
 
 int fdt_size_cells(const void *fdt, int nodeoffset)
 {
-	return fdt_cells(fdt, nodeoffset, "#size-cells");
+	int val;
+
+	val = fdt_cells(fdt, nodeoffset, "#size-cells");
+	if (val == -FDT_ERR_NOTFOUND)
+		return 1;
+	return val;
 }
diff --git a/scripts/dtc/libfdt/libfdt.h b/scripts/dtc/libfdt/libfdt.h
index 66f01fe..5c778b1 100644
--- a/scripts/dtc/libfdt/libfdt.h
+++ b/scripts/dtc/libfdt/libfdt.h
@@ -1109,7 +1109,7 @@
  *
  * returns:
  *	0 <= n < FDT_MAX_NCELLS, on success
- *      2, if the node has no #size-cells property
+ *      1, if the node has no #size-cells property
  *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
  *		#size-cells property
  *	-FDT_ERR_BADMAGIC,