meta-romulus: Add CPLD workaround

Romulus power on scripts requires a workaround to trigger CPLD to give
pgood signal after vcs_workaround.
Add this as cpld_trigger service that runs after vcs_workaround and
before obmc-host-start-pre.

Change-Id: I0723bad38a5832f0bb2a8776129885308a8e644a
Signed-off-by: Lei YU <mine260309@gmail.com>
4 files changed