FAFT: Fix keyboard developer mode support

Sometimes the EC_IN_RW signal is already set, and we need a cold reset
to clear it. Also change EC reboot from hard reboot to soft reboot.

TEST=Successfully switch to developer mode

Change-Id: I7e73e7d92d94f549f87ed3a2b67653c3cf869afb
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/30983
Reviewed-by: Tom Wai-Hong Tam <waihong@chromium.org>
1 file changed