cheza: Apply the fix to handle two or more HPD events
cheza: Apply the fix to handle two or more HPD events

Apply the following fix to Cheza:
  http://crrev.com/c/388737

Some Type-C to DP adapters generate two or more HPD events while
others generate only one HPD event. Currently hotplugging only
works with the former adapter. Now hotplugging is triggered on
one or more HPD events.

BRANCH=none
BUG=b:118838389
TEST=Plugged and unplugged a USB-C hub with HDMI port to port-0.
Plugged and unplugged a HDMI monitor cable to the above hub.
Checked the "typec 0" command showing proper results.

Change-Id: If03e3db049fb3ba4de0f52b5084fd0457e3703d5
Signed-off-by: Wai-Hong Tam <04b587fdf5845741a0c5a8b9cd59ca72d73ef8fc@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1313473
Reviewed-by: Stephen Boyd <eeb31768d3df4444d6703fd44d40e628b44c8e77@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec