dt-bindings: memory-controller: Document Broadcom STB MEMC

Document the Broadcom STB memory controller which is a trivial binding
for now with a set of compatible strings and single register.

Since we introduce this binding, the section in
Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt is removed
and this binding is referenced instead.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
[krzk: correct path in brcm,brcmstb.txt]
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220812222533.2428033-2-f.fainelli@gmail.com

Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt

@@ -187,15 +187,8 @@ Required properties:
 Sequencer DRAM parameters and control registers. Used for Self-Refresh
 Power-Down (SRPD), among other things.
 
-Required properties:
-- compatible     : should contain one of these
-	"brcm,brcmstb-memc-ddr-rev-b.2.1"
-	"brcm,brcmstb-memc-ddr-rev-b.2.2"
-	"brcm,brcmstb-memc-ddr-rev-b.2.3"
-	"brcm,brcmstb-memc-ddr-rev-b.3.0"
-	"brcm,brcmstb-memc-ddr-rev-b.3.1"
-	"brcm,brcmstb-memc-ddr"
-- reg            : the MEMC DDR register range
+See Documentation/devicetree/bindings/memory-controllers/brcm,brcmstb-memc-ddr.yaml for a
+full list of supported compatible strings and properties.
 
 Example:
 

Documentation/devicetree/bindings/memory-controllers/brcm,brcmstb-memc-ddr.yaml

@@ -0,0 +1,52 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/memory-controllers/brcm,brcmstb-memc-ddr.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Memory controller (MEMC) for Broadcom STB
+
+maintainers:
+  - Florian Fainelli <f.fainelli@gmail.com>
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - brcm,brcmstb-memc-ddr-rev-b.1.x
+          - brcm,brcmstb-memc-ddr-rev-b.2.0
+          - brcm,brcmstb-memc-ddr-rev-b.2.1
+          - brcm,brcmstb-memc-ddr-rev-b.2.2
+          - brcm,brcmstb-memc-ddr-rev-b.2.3
+          - brcm,brcmstb-memc-ddr-rev-b.2.5
+          - brcm,brcmstb-memc-ddr-rev-b.2.6
+          - brcm,brcmstb-memc-ddr-rev-b.2.7
+          - brcm,brcmstb-memc-ddr-rev-b.2.8
+          - brcm,brcmstb-memc-ddr-rev-b.3.0
+          - brcm,brcmstb-memc-ddr-rev-b.3.1
+          - brcm,brcmstb-memc-ddr-rev-c.1.0
+          - brcm,brcmstb-memc-ddr-rev-c.1.1
+          - brcm,brcmstb-memc-ddr-rev-c.1.2
+          - brcm,brcmstb-memc-ddr-rev-c.1.3
+          - brcm,brcmstb-memc-ddr-rev-c.1.4
+      - const: brcm,brcmstb-memc-ddr
+
+  reg:
+    maxItems: 1
+
+  clock-frequency:
+    description: DDR PHY frequency in Hz
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    memory-controller@9902000 {
+        compatible = "brcm,brcmstb-memc-ddr-rev-c.1.1", "brcm,brcmstb-memc-ddr";
+        reg = <0x9902000 0x600>;
+        clock-frequency = <2133000000>;
+    };