dt-bindings: clock: Convert marvell,mmp2-clock to json-schema

Convert the fixed-factor-clock binding to DT schema format using
json-schema.

While at that, fix a couple of small errors: make the file base name
match the compatible string, add an example and document the reg-names
property.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lkml.kernel.org/r/20200309194254.29009-4-lkundrak@v3.skSigned-off-by: Stephen Boyd <sboyd@kernel.org>

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

+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/marvell,mmp2-clock.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Marvell MMP2 Clock Controller
+
+maintainers:
+  - Lubomir Rintel <lkundrak@v3.sk>
+
+description: |
+  The MMP2 clock subsystem generates and supplies clock to various
+  controllers within the MMP2 SoC.
+
+  Each clock is assigned an identifier and client nodes use this identifier
+  to specify the clock which they consume.
+
+  All these identifiers could be found in <dt-bindings/clock/marvell,mmp2.h>.
+
+properties:
+  compatible:
+    const: marvell,mmp2-clock # controller compatible with MMP2 SoC
+
+  reg:
+    items:
+      - description: MPMU register region
+      - description: APMU register region
+      - description: APBC register region
+
+  reg-names:
+    items:
+      - const: mpmu
+      - const: apmu
+      - const: apbc
+
+  '#clock-cells':
+    const: 1
+
+  '#reset-cells':
+    const: 1
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - '#clock-cells'
+  - '#reset-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    clock-controller@d4050000 {
+      compatible = "marvell,mmp2-clock";
+      reg = <0xd4050000 0x1000>,
+            <0xd4282800 0x400>,
+            <0xd4015000 0x1000>;
+      reg-names = "mpmu", "apmu", "apbc";
+      #clock-cells = <1>;
+      #reset-cells = <1>;
+    };

Documentation/devicetree/bindings/clock/marvell,mmp2.txt

-* Marvell MMP2 Clock Controller
-
-The MMP2 clock subsystem generates and supplies clock to various
-controllers within the MMP2 SoC.
-
-Required Properties:
-
-- compatible: should be one of the following.
-  - "marvell,mmp2-clock" - controller compatible with MMP2 SoC.
-
-- reg: physical base address of the clock subsystem and length of memory mapped
-  region. There are 3 places in SOC has clock control logic:
-  "mpmu", "apmu", "apbc". So three reg spaces need to be defined.
-
-- #clock-cells: should be 1.
-- #reset-cells: should be 1.
-
-Each clock is assigned an identifier and client nodes use this identifier
-to specify the clock which they consume.
-
-All these identifiers could be found in <dt-bindings/clock/marvell,mmp2.h>.