ARM: shmobile: r8a73a4 dtsi: Add SoC-specific thermal compatible property

The thermal node used the generic compatible property only.
Add the SoC-specific one, to make it future proof.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a73a4.dtsi

@@ -165,7 +165,7 @@ dma0: dma-controller@e6700020 {
 	};
 
 	thermal@e61f0000 {
-		compatible = "renesas,rcar-thermal";
+		compatible = "renesas,thermal-r8a73a4", "renesas,rcar-thermal";
 		reg = <0 0xe61f0000 0 0x14>, <0 0xe61f0100 0 0x38>,
 			 <0 0xe61f0200 0 0x38>, <0 0xe61f0300 0 0x38>;
 		interrupts = <0 69 IRQ_TYPE_LEVEL_HIGH>;