ARM: dts: r8a7779: Remove deprecated "renesas, rcar-sata" compatible value

The "renesas,rcar-sata" compatible value was deprecated by
"renesas,sata-r8a7779" many years ago, in commit e67adb4e
("sata_rcar: Add R-Car Gen2 SATA PHY support").  Drop it.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/20200219153929.11073-1-geert+renesas@glider.be

arch/arm/boot/dts/r8a7779.dtsi

@@ -377,7 +377,7 @@ tmu2: timer@ffd82000 {
 	};
 
 	sata: sata@fc600000 {
-		compatible = "renesas,sata-r8a7779", "renesas,rcar-sata";
+		compatible = "renesas,sata-r8a7779";
 		reg = <0xfc600000 0x200000>;
 		interrupts = <GIC_SPI 100 IRQ_TYPE_LEVEL_HIGH>;
 		clocks = <&mstp1_clks R8A7779_CLK_SATA>;