sandbox: dt: add sandbox_tee node

Adds a sandbox_tee node to enable the sandbox tee driver in all the
sandbox dts files.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

arch/sandbox/dts/sandbox.dts

@@ -342,6 +342,10 @@
 			status = "okay";
 		};
 	};
+
+	sandbox_tee {
+		compatible = "sandbox,tee";
+	};
 };
 
 #include "cros-ec-keyboard.dtsi"

arch/sandbox/dts/sandbox64.dts

@@ -311,6 +311,10 @@
 			};
 		};
 	};
+
+	sandbox_tee {
+		compatible = "sandbox,tee";
+	};
 };
 
 #include "cros-ec-keyboard.dtsi"

arch/sandbox/dts/test.dts

@@ -657,6 +657,10 @@
 	board {
 		compatible = "sandbox,board_sandbox";
 	};
+
+	sandbox_tee {
+		compatible = "sandbox,tee";
+	};
 };
 
 #include "sandbox_pmic.dtsi"