dt-bindings: interrupt-controller: Merge BCM3380 with BCM7120

The two bindings are very similar and should be covered by the same
document, do that so we can get rid of an additional binding file.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211217160546.497012-3-f.fainelli@gmail.com

Documentation/devicetree/bindings/interrupt-controller/brcm,bcm7120-l2-intc.yaml

@@ -4,7 +4,7 @@
 $id: http://devicetree.org/schemas/interrupt-controller/brcm,bcm7120-l2-intc.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: Broadcom BCM7120-style Level 2 interrupt controller
+title: Broadcom BCM7120-style Level 2 and Broadcom BCM3380 Level 1 / Level 2
 
 maintainers:
   - Florian Fainelli <f.fainelli@gmail.com>
@@ -59,15 +59,29 @@ description: >
   ..
   31 ........................ X
 
+  The BCM3380 Level 1 / Level 2 interrrupt controller shows up in various forms
+  on many BCM338x/BCM63xx chipsets. It has the following properties:
+
+  - outputs a single interrupt signal to its interrupt controller parent
+
+  - contains one or more enable/status word pairs, which often appear at
+    different offsets in different blocks
+
+  - no atomic set/clear operations
+
 allOf:
   - $ref: /schemas/interrupt-controller.yaml#
 
 properties:
   compatible:
-    const: brcm,bcm7120-l2-intc
+    items:
+      - enum:
+          - brcm,bcm7120-l2-intc
+          - brcm,bcm3380-l2-intc
 
   reg:
-    maxItems: 1
+    minItems: 1
+    maxItems: 4
     description: >
       Specifies the base physical address and size of the registers
 
@@ -124,3 +138,14 @@ examples:
       brcm,int-map-mask = <0xeb8>, <0x140>;
       brcm,int-fwd-mask = <0x7>;
     };
+
+  - |
+    irq1_intc: interrupt-controller@10000020 {
+       compatible = "brcm,bcm3380-l2-intc";
+       reg = <0x10000024 0x4>, <0x1000002c 0x4>,
+             <0x10000020 0x4>, <0x10000028 0x4>;
+       interrupt-controller;
+       #interrupt-cells = <1>;
+       interrupt-parent = <&cpu_intc>;
+       interrupts = <2>;
+    };