Update firmware when only preamble changes

Currently when set_firmware_version is called, firmware is only updated
when version changed. Let's change this to also update on flags change.

BUG=chrome-os-partner:11980
TEST=Tested we can clear RO-normal flag.

Change-Id: If24d399ea3f5761e602207d4df70201926277522
Reviewed-on: https://gerrit.chromium.org/gerrit/28785
Reviewed-by: Tom Wai-Hong Tam <waihong@chromium.org>
Commit-Ready: Vic Yang <victoryang@chromium.org>
Tested-by: Vic Yang <victoryang@chromium.org>
1 file changed