arm64: dts: qcom: sdm845: Add the missing clocks on the dispcc

arm64: dts: qcom: sdm845: Add the missing clocks on the dispcc

We're transitioning over to requiring the Qualcomm Display Clock
Controller to specify all the input clocks.  Let's add them for
sdm845.

NOTES:
- Until the Linux driver for sdm845's dispcc is updated, these clocks
  will not actually be used in Linux.  It will continue to use global
  clock names to match things up.
- Although the clocks from the DP PHY are required, the DP PHY isn't
  represented in the dts yet.  Apparently the magic for this is just
  to use <0>.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200203103049.v4.3.Ie80fa74e1774f4317d80d70d30ef4b78f16cc8df@changeid
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>