[PATCH v3 5/9] Documentation: DT: add entries for I2SE boards

This patch adds the missing devicetree binding documentation for I2SE's
Duckbill and Duckbill 2 series boards.

Signed-off-by: Michael Heimpold <redacted>
Cc: Stefan Wahren <redacted>
---
 Documentation/devicetree/bindings/arm/i2se.txt | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/i2se.txt

diff --git a/Documentation/devicetree/bindings/arm/i2se.txt b/Documentation/devicetree/bindings/arm/i2se.txt
new file mode 100644
index 0000000..9954d86
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/i2se.txt

@@ -0,0 +1,22 @@
+I2SE Device Tree Bindings
+-------------------------
+
+Duckbill Board
+Required root node properties:
+    - compatible = "i2se,duckbill", "fsl,imx28";
+
+Duckbill 2 Board
+Required root node properties:
+    - compatible = "i2se,duckbill", "fsl,imx28";
+
+Duckbill 2 485 Board
+Required root node properties:
+    - compatible = "i2se,duckbill", "fsl,imx28";
+
+Duckbill 2 EnOcean Board
+Required root node properties:
+    - compatible = "i2se,duckbill", "fsl,imx28";
+
+Duckbill 2 SPI Board
+Required root node properties:
+    - compatible = "i2se,duckbill", "fsl,imx28";