dt-bindings: clock: Add MMP3 compatible string

This binding describes the PMUs that are found on MMP3 as well. Add the
compatible strings and adjust the description.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lkml.kernel.org/r/20200309194254.29009-7-lkundrak@v3.skSigned-off-by: Stephen Boyd <sboyd@kernel.org>

Documentation/devicetree/bindings/clock/marvell,mmp2-clock.yaml

@@ -4,14 +4,14 @@
 $id: http://devicetree.org/schemas/clock/marvell,mmp2-clock.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: Marvell MMP2 Clock Controller
+title: Marvell MMP2 and MMP3 Clock Controller
 
 maintainers:
   - Lubomir Rintel <lkundrak@v3.sk>
 
 description: |
-  The MMP2 clock subsystem generates and supplies clock to various
-  controllers within the MMP2 SoC.
+  The clock subsystem on MMP2 or MMP3 generates and supplies clock to various
+  controllers within the SoC.
 
   Each clock is assigned an identifier and client nodes use this identifier
   to specify the clock which they consume.
@@ -20,7 +20,9 @@ description: |
 
 properties:
   compatible:
-    const: marvell,mmp2-clock # controller compatible with MMP2 SoC
+    enum:
+      - marvell,mmp2-clock # controller compatible with MMP2 SoC
+      - marvell,mmp3-clock # controller compatible with MMP3 SoC
 
   reg:
     items: