dt-bindings: display: add Unisoc's mipi dsi controller bindings

Adds MIPI DSI Controller
support for Unisoc's display subsystem.

v5:
  - Remove panel_in port for dsi node.

Cc: Orson Zhai <orsonzhai@gmail.com>
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Signed-off-by: Kevin Tang <kevin.tang@unisoc.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211207142717.30296-6-kevin3.tang@gmail.com

Documentation/devicetree/bindings/display/sprd/sprd,sharkl3-dsi-host.yaml

@@ -0,0 +1,88 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/sprd/sprd,sharkl3-dsi-host.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Unisoc MIPI DSI Controller
+
+maintainers:
+  - Kevin Tang <kevin.tang@unisoc.com>
+
+properties:
+  compatible:
+    const: sprd,sharkl3-dsi-host
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 2
+
+  clocks:
+    minItems: 1
+
+  clock-names:
+    items:
+      - const: clk_src_96m
+
+  power-domains:
+    maxItems: 1
+
+  ports:
+    type: object
+
+    properties:
+      "#address-cells":
+        const: 1
+
+      "#size-cells":
+        const: 0
+
+      port@0:
+        type: object
+        description:
+          A port node with endpoint definitions as defined in
+          Documentation/devicetree/bindings/media/video-interfaces.txt.
+          That port should be the input endpoint, usually coming from
+          the associated DPU.
+
+    required:
+      - "#address-cells"
+      - "#size-cells"
+      - port@0
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+  - ports
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/clock/sprd,sc9860-clk.h>
+    dsi: dsi@63100000 {
+        compatible = "sprd,sharkl3-dsi-host";
+        reg = <0x63100000 0x1000>;
+        interrupts = <GIC_SPI 48 IRQ_TYPE_LEVEL_HIGH>,
+          <GIC_SPI 49 IRQ_TYPE_LEVEL_HIGH>;
+        clock-names = "clk_src_96m";
+        clocks = <&pll CLK_TWPLL_96M>;
+        ports {
+            #address-cells = <1>;
+            #size-cells = <0>;
+            port@0 {
+                reg = <0>;
+                dsi_in: endpoint {
+                    remote-endpoint = <&dpu_out>;
+                };
+            };
+        };
+    };