sql/Makefile: Install sql files under doc/.../sql subdir

Change-Id: I1c9008d4692412a0cfe39d05216fc9c857cf1e8a
diff --git a/sql/Makefile.am b/sql/Makefile.am
index 1367cf2..75be70e 100644
--- a/sql/Makefile.am
+++ b/sql/Makefile.am
@@ -3,5 +3,5 @@
 	hlr.sql \
 	$(NULL)
 
-docsdir = $(docdir)
-docs_DATA = $(srcdir)/hlr.sql $(srcdir)/hlr_data.sql
+sqldir = $(docdir)/sql
+sql_DATA = $(srcdir)/hlr.sql $(srcdir)/hlr_data.sql