dm: Add a debug message when devices are skipped pre-reloc

This adds a message to lists_bind_fdt when it skips initializing a device
pre-relocation. I've had a couple errors where a device didn't initialize
properly because one of its dependencies was missing.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/core/lists.c b/drivers/core/lists.c
index 4681b3e..68204c3 100644
--- a/drivers/core/lists.c
+++ b/drivers/core/lists.c
@@ -176,8 +176,10 @@
 
 		if (pre_reloc_only) {
 			if (!dm_ofnode_pre_reloc(node) &&
-			    !(entry->flags & DM_FLAG_PRE_RELOC))
+			    !(entry->flags & DM_FLAG_PRE_RELOC)) {
+				log_debug("Skipping device pre-relocation\n");
 				return 0;
+			}
 		}
 
 		log_debug("   - found match at '%s': '%s' matches '%s'\n",