dt-bindings: display: msm: mdp4: add LCDC clock and PLL source

dt-bindings: display: msm: mdp4: add LCDC clock and PLL source

Add the LCDC / LVDS clock input and the XO used to drive internal LVDS
PLL to MDP4 controller bindings. The controller also provides LVDS PHY
PLL, so add optional #clock-cells to the device.

Acked-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/650278/
Link: https://lore.kernel.org/r/20250425-fd-mdp4-lvds-v4-1-6b212160b44c@oss.qualcomm.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>