arm64: dt: hikey: Add optee node

Acked-by: NWei Xu <xuwei5@hisilicon.com>
Signed-off-by: NJerome Forissier <jerome.forissier@linaro.org>
Signed-off-by: NJens Wiklander <jens.wiklander@linaro.org>

arch/arm64/boot/dts/hisilicon/hi6220-hikey.dts

@@ -406,6 +406,13 @@
 			};
 		};
 	};
+
+	firmware {
+		optee {
+			compatible = "linaro,optee-tz";
+			method = "smc";
+		};
+	};
 };
 
 &uart2 {