ARM: dts: imx6qdl-tqma6: improve compatible for LM75 temp sensor

Use national,lm75a to specify exact variant used. This should cause
no functional changes.

While at it change node name to 'temperature-sensor@48' to
describe the function of the IC.

Signed-off-by: Markus Niebel <Markus.Niebel@ew.tq-group.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/nxp/imx/imx6qdl-tqma6a.dtsi

@@ -27,8 +27,8 @@
 		reg = <0x08>;
 	};
 
-	sensor@48 {
-		compatible = "national,lm75";
+	temperature-sensor@48 {
+		compatible = "national,lm75a";
 		reg = <0x48>;
 		vs-supply = <&reg_3p3v>;
 	};

arch/arm/boot/dts/nxp/imx/imx6qdl-tqma6b.dtsi

@@ -20,8 +20,8 @@
 		reg = <0x08>;
 	};
 
-	sensor@48 {
-		compatible = "national,lm75";
+	temperature-sensor@48 {
+		compatible = "national,lm75a";
 		reg = <0x48>;
 		vs-supply = <&reg_3p3v>;
 	};