Document softmmu templates

Add some comments to describe each file.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
diff --git a/softmmu_template.h b/softmmu_template.h
index c2df9ec..ae0ccf2 100644
--- a/softmmu_template.h
+++ b/softmmu_template.h
@@ -1,6 +1,11 @@
 /*
  *  Software MMU support
  *
+ * Generate helpers used by TCG for qemu_ld/st ops and code load
+ * functions.
+ *
+ * Included from target op helpers and exec.c.
+ *
  *  Copyright (c) 2003 Fabrice Bellard
  *
  * This library is free software; you can redistribute it and/or