dt-bindings: timestamp: Add Tegra234 support

Added timestamp provider support for the Tegra234 in devicetree
bindings. From Tegra234 SoC onwards, the nvidia,gpio-controller
property is required. This is needed as the tegra always-on (AON) GPIO
HTE/GTE provider depends on the AON GPIO controller where it needs to
do namespace conversion between GPIO line number (belonging to AON
GPIO controller instance) and the GTE slice bits.
Signed-off-by: Dipen Patel <dipenp@nvidia.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Documentation/devicetree/bindings/timestamp/nvidia,tegra194-hte.yaml

@@ -4,7 +4,7 @@
 $id: http://devicetree.org/schemas/timestamp/nvidia,tegra194-hte.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: Tegra194 on chip generic hardware timestamping engine (HTE)
+title: Tegra on chip generic hardware timestamping engine (HTE) provider
 
 maintainers:
   - Dipen Patel <dipenp@nvidia.com>
@@ -23,6 +23,8 @@ properties:
     enum:
       - nvidia,tegra194-gte-aon
       - nvidia,tegra194-gte-lic
+      - nvidia,tegra234-gte-aon
+      - nvidia,tegra234-gte-lic
 
   reg:
     maxItems: 1
@@ -43,9 +45,14 @@ properties:
     description:
       HTE lines are arranged in 32 bit slice where each bit represents different
       line/signal that it can enable/configure for the timestamp. It is u32
-      property and depends on the HTE instance in the chip. The value 3 is for
-      GPIO GTE and 11 for IRQ GTE.
-    enum: [3, 11]
+      property and the value depends on the HTE instance in the chip.
+    enum: [3, 11, 17]
+
+  nvidia,gpio-controller:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      The phandle to AON gpio controller instance. This is required to handle
+      namespace conversion between GPIO and GTE.
 
   '#timestamp-cells':
     description:
@@ -62,6 +69,51 @@ required:
   - nvidia,slices
   - "#timestamp-cells"
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - nvidia,tegra194-gte-aon
+              - nvidia,tegra234-gte-aon
+    then:
+      properties:
+        nvidia,slices:
+          const: 3
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - nvidia,tegra194-gte-lic
+    then:
+      properties:
+        nvidia,slices:
+          const: 11
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - nvidia,tegra234-gte-lic
+    then:
+      properties:
+        nvidia,slices:
+          const: 17
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - nvidia,tegra234-gte-aon
+    then:
+      required:
+        - nvidia,gpio-controller
+
 additionalProperties: false
 
 examples: