gitignore: Add new generated files
gitignore: Add new generated files

Some files are now generated that didn't exist before.

Change-Id: Ib1153496cba30688aecb939e3e1cc7acc7e744c9
Signed-off-by: William A. Kennington III <30fff5198f4d10ca1117e5f3ec82f3b4b8900d81@google.com>

openbmc/phosphor-networkd,openbmc/phosphor-networkd