dm: core: Drop ofnode_is_available()

This function is also available as ofnode_is_enabled(), so use that
instead.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/pci/pci_tegra.c b/drivers/pci/pci_tegra.c
index bc489d5..29d5411 100644
--- a/drivers/pci/pci_tegra.c
+++ b/drivers/pci/pci_tegra.c
@@ -531,7 +531,7 @@
 
 		lanes |= num_lanes << (index << 3);
 
-		if (!ofnode_is_available(subnode))
+		if (!ofnode_is_enabled(subnode))
 			continue;
 
 		port = malloc(sizeof(*port));