faft: Skip tests on embedded devices

The following 3 tests are not suitable for embedded devices. Skip
them by raising TestNAError.
  firmware_DevScreenTimeout
  firmware_FwScreenCloseLid
  firmware_FwScreenPressPower

BUG=chrome-os-partner:34513
TEST=None

Change-Id: I6acdff9459aafda31e8206325a1d5410959ed89a
Reviewed-on: https://chromium-review.googlesource.com/273362
Trybot-Ready: Tom Tam <waihong@google.com>
Tested-by: Tom Tam <waihong@google.com>
Reviewed-by: Yusuf Mohsinally <mohsinally@chromium.org>
Commit-Queue: Tom Tam <waihong@google.com>
Reviewed-by: danny chan <dchan@chromium.org>
3 files changed