Add displayport altmode declaration to the Type-C controller node to
enable DP altmode negotiation.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20230817145940.9887-5-dmitry.baryshkov@linaro.orgSigned-off-by: Bjorn Andersson <andersson@kernel.org>