.gitignore: add autom4te.cache
.gitignore: add autom4te.cache

Add autom4te.cache to .gitignore file.

Change-Id: I4b246860edc94dd31e844badc7ddfa54febe50fb
Signed-off-by: Patrick Venture <36c53fa43f47f3fd67cb2fc38031827244d18a1f@google.com>

openbmc/phosphor-ipmi-flash