build_image: don't force tpm use flag for factory images

Don't add tpm to USE flags when building factory images

BUG=chrome-os-partner:55836
TEST=build_image --board=kevin-tpm2 factory_install

Change-Id: I5d41e3b3e0e66d5d4e8ba0cb76302630dfed1686
Reviewed-on: https://chromium-review.googlesource.com/365510
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
1 file changed