fdtdec: Support retrieving the name of a carveout

When retrieving a given carveout for a device, allow callers to query
the name. This helps differentiating between carveouts when there are
more than one.

This is also useful when copying carveouts to help assign a meaningful
name that cannot always be guessed.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index f2861eb..3ada77d 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -1406,8 +1406,9 @@
 	return 0;
 }
 
-int fdtdec_get_carveout(const void *blob, const char *node, const char *name,
-			unsigned int index, struct fdt_memory *carveout)
+int fdtdec_get_carveout(const void *blob, const char *node,
+			const char *prop_name, unsigned int index,
+			struct fdt_memory *carveout, const char **name)
 {
 	const fdt32_t *prop;
 	uint32_t phandle;
@@ -1418,9 +1419,9 @@
 	if (offset < 0)
 		return offset;
 
-	prop = fdt_getprop(blob, offset, name, &len);
+	prop = fdt_getprop(blob, offset, prop_name, &len);
 	if (!prop) {
-		debug("failed to get %s for %s\n", name, node);
+		debug("failed to get %s for %s\n", prop_name, node);
 		return -FDT_ERR_NOTFOUND;
 	}
 
@@ -1442,6 +1443,9 @@
 		return offset;
 	}
 
+	if (name)
+		*name = fdt_get_name(blob, offset, NULL);
+
 	carveout->start = fdtdec_get_addr_size_auto_noparent(blob, offset,
 							     "reg", 0, &size,
 							     true);