dm: syscon: Fix calling dev_dbg with an uninitialized device

We can't use dev_dbg here because we haven't bound to the device yet. Use
log_debug instead.
Signed-off-by: NSean Anderson <seanga2@gmail.com>
Reviewed-by: NPatrick Delaunay <patrick.delaunay@st.com>
Tested-by: NPatrick Delaunay <patrick.delaunay@st.com>

drivers/core/syscon-uclass.c

@@ -70,7 +70,7 @@ static int syscon_probe_by_ofnode(ofnode node, struct udevice **devp)
 
 	/* found node with "syscon" compatible, not bounded to SYSCON UCLASS */
 	if (!ofnode_device_is_compatible(node, "syscon")) {
-		dev_dbg(dev, "invalid compatible for syscon device\n");
+		log_debug("invalid compatible for syscon device\n");
 		return -EINVAL;
 	}