subprojects: Add everything for local building

This makes it more trivial to build without the CI

Change-Id: I6ff0e8b128a870f89fcc9c1462b71d29f85d6117
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/.gitignore b/.gitignore
index 7fdf4d4..7712532 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,5 @@
 /build*/
 /subprojects/*
+!/subprojects/phosphor-dbus-interfaces.wrap
+!/subprojects/sdbusplus.wrap
+!/subprojects/sdeventplus.wrap