fdt: update fdt_alloc_phandle to use fdt_get_phandle

The device tree compiler, dtc, can use "phandle" and/or "linux,phandle"
properties to specify the phandle for any node.  By default, it uses
both, but "linux,phandle" is deprecated.  One day, we'd like to stop using
"linux,phandle", but U-boot needs to support both properties equally
first.

fdt_alloc_phandle() generates a unique phandle, but it was only checking
the "linux,phandle" properties.  Instead, we use fdt_get_phandle(),
which checks both properties automatically.  This ensures that we
support dtbs that only use "phandle".

The side-effect is that fdt_alloc_phandle() now takes twice as long, since
it has to check for two properties instead of one in each node that it
searches.

Signed-off-by: Timur Tabi <timur@freescale.com>

common/fdt_support.c

@@ -1182,14 +1182,11 @@ int fdt_node_offset_by_compat_reg(void *blob, const char *compat,
  */
 int fdt_alloc_phandle(void *blob)
 {
-	int offset, len, phandle = 0;
-	const u32 *val;
+	int offset, phandle = 0;
 
 	for (offset = fdt_next_node(blob, -1, NULL); offset >= 0;
 	     offset = fdt_next_node(blob, offset, NULL)) {
-		val = fdt_getprop(blob, offset, "linux,phandle", &len);
-		if (val)
-			phandle = max(*val, phandle);
+		phandle = max(phandle, fdt_get_phandle(blob, offset));
 	}
 
 	return phandle + 1;