ARM: dts: pbab01: correct rtc vendor

The rtc8564 is made by Epson but is similar to the NXP pcf8563. Use the
correct vendor name.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6qdl-phytec-pbab01.dtsi

@@ -128,7 +128,7 @@ stmpe@41 {
 	};
 
 	rtc@51 {
-		compatible = "nxp,rtc8564";
+		compatible = "epson,rtc8564";
 		reg = <0x51>;
 	};