dt-bindings: clock: qcom,mmcc: Add GPLL0_DIV for MSM8998

We've not been consuming that clock for no apparent reason. Describe it.

Acked-by: Krzysztof Kozlowski <[e-mail]>
Acked-by: Rob Herring <[e-mail]>
Acked-by: Jeffrey Hugo <[e-mail]>
Signed-off-by: Konrad Dybcio <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Bjorn Andersson <[e-mail]>

Documentation/devicetree/bindings/clock/qcom,mmcc.yaml

···
             - description: HDMI phy PLL clock
             - description: DisplayPort phy PLL link clock
             - description: DisplayPort phy PLL vco clock
+            - description: Global PLL 0 DIV clock
 
         clock-names:
           items:
···
             - const: hdmipll
             - const: dplink
             - const: dpvco
+            - const: gpll0_div
 
   - if:
       properties: