Don't tidy/format files in subproject

This pattern and files are copied from bmcweb.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: If048cbd458bb7e1bcf704daf60cf060af359ef81
diff --git a/.gitignore b/.gitignore
index 07e92ea..8c17b65 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,8 @@
 build*/*
-subprojects/*/
+subprojects/*
+!subprojects/*.wrap
+!subprojects/.clang-tidy
+!subprojects/.clang-format
 boost-src
 Boost-prefix
 CMakeFiles