rename WORDS_BIGENDIAN to HOST_WORDS_BIGENDIAN

Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/hw/gus.c b/hw/gus.c
index 8915d43..5e73c5a 100644
--- a/hw/gus.c
+++ b/hw/gus.c
@@ -35,7 +35,7 @@
 #define ldebug(...)
 #endif
 
-#ifdef WORDS_BIGENDIAN
+#ifdef HOST_WORDS_BIGENDIAN
 #define GUS_ENDIANNESS 1
 #else
 #define GUS_ENDIANNESS 0