ec: Add .gdb_history to .gitignore
ec: Add .gdb_history to .gitignore

Add .gdb_history to .gitignore.

BRANCH=None
BUG=None
TEST=None

Signed-off-by: Jeremy Bettis <4df7b5147fee087dca33c181f288ee7dbf56e022@google.com>
Change-Id: Ibb52970914fe8e68aa7b1bc6700a03aae3a6bc42
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3384481
Tested-by: Jeremy Bettis <4df7b5147fee087dca33c181f288ee7dbf56e022@chromium.org>
Auto-Submit: Jeremy Bettis <4df7b5147fee087dca33c181f288ee7dbf56e022@chromium.org>
Reviewed-by: Daisuke Nojiri <fd5f93af191bf7e8f73ea71cc3c0f66b41b1dd49@chromium.org>
Commit-Queue: Jeremy Bettis <4df7b5147fee087dca33c181f288ee7dbf56e022@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec