dt-bindings: Add devicetree bindings

Add snapshot of device tree bindings from keystone common kernel, branch
"android-mainline-keystone-qcom-release" at c4c12103f9c0 ("Snap for 9228065
from e32903b9a63bb558df8b803b076619c53c16baad to
android-mainline-keystone-qcom-release").

Change-Id: I7682079615cbd9f29340a5c1f2a1d84ec441a1f1
Signed-off-by: Melody Olvera <quic_molvera@quicinc.com>

bindings/memory-controllers/calxeda-ddr-ctrlr.yaml

@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/memory-controllers/calxeda-ddr-ctrlr.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Calxeda DDR memory controller binding
+
+description: |
+  The Calxeda DDR memory controller is initialised and programmed by the
+  firmware, but an OS might want to read its registers for error reporting
+  purposes and to learn about the DRAM topology.
+
+maintainers:
+  - Andre Przywara <andre.przywara@arm.com>
+
+properties:
+  compatible:
+    enum:
+      - calxeda,hb-ddr-ctrl
+      - calxeda,ecx-2000-ddr-ctrl
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    memory-controller@fff00000 {
+        compatible = "calxeda,hb-ddr-ctrl";
+        reg = <0xfff00000 0x1000>;
+        interrupts = <0 91 4>;
+    };