Add support for delayed HPD toggle

This introduces a ScheduleHpdToggle routine (as part of the XMLRPC API),
that allows scheduling a delayed HPD toggle. This is especially useful
when testing HPD plug/unplug during suspend/hibernate from the DUT
itself.

Bug=None
Test=Call the XMLRPC method and ensure a delayed HPD toggle occurs

Change-Id: Ifcae70ae180f56405baaba137f83c2233a47358e
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@linux.intel.com>
Reviewed-on: https://chromium-review.googlesource.com/541378
Reviewed-by: Cheng-Yi Chiang <cychiang@chromium.org>
4 files changed