gitignore: Fix subprojects
gitignore: Fix subprojects

Change-Id: Ib60275837c28eaa7d4f2d9da0181ea63f8a23d17
Signed-off-by: William A. Kennington III <30fff5198f4d10ca1117e5f3ec82f3b4b8900d81@google.com>

openbmc/stdplus,openbmc/stdplus