Makefile: rename all libraries to built-in.o

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/arch/microblaze/cpu/u-boot.lds b/arch/microblaze/cpu/u-boot.lds
index 3e6204d..fdad207 100644
--- a/arch/microblaze/cpu/u-boot.lds
+++ b/arch/microblaze/cpu/u-boot.lds
@@ -30,7 +30,7 @@
 	{
 		__data_start = .;
 #ifdef CONFIG_OF_EMBED
-		dts/libdts.o (.data)
+		dts/built-in.o (.data)
 #endif
 		*(.data)
 		__data_end = .;