faft: Support EC hostevent in Chrome EC class

We set the EC hostevent to emulate the keyboard recovery combination
(Esc+Refresh+Power) has been pressed. Such that on EC reboot, it triggers
the same recovery path.

This CL wraps the underlying hostevent command into a method. It makes
the hostevent more easy to be used without knowing any detail of the EC
command.

BUG=chromium-os:35254
TEST=run_remote_tests.sh --board link --remote dut RecoveryButton/control$

Change-Id: I565a933e0f9ba775386d66120eef02e543a2a48c
Reviewed-on: https://gerrit.chromium.org/gerrit/36868
Reviewed-by: Vic Yang <victoryang@chromium.org>
Commit-Ready: Tom Wai-Hong Tam <waihong@chromium.org>
Tested-by: Tom Wai-Hong Tam <waihong@chromium.org>
2 files changed