dt-bindings: connector: Add PD rev 2.0 VDO definition

Add the VDO definition for USB PD rev 2.0 in the bindings and define a
new property snk-vdos-v1 containing legacy VDOs as the responses to the
port partner which only supports PD rev 2.0.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kyle Tso <kyletso@google.com>
Link: https://lore.kernel.org/r/20210601123151.3441914-3-kyletso@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>