watchdog: sp805_wdt: use correct compatible string

According to the linux device tree specification the compatible string
is:
  compatible = "arm,sp805", "arm,primecell";

Fix all users in u-boot.

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
diff --git a/arch/arm/dts/hi3660.dtsi b/arch/arm/dts/hi3660.dtsi
index 65a45b0..028f4db 100644
--- a/arch/arm/dts/hi3660.dtsi
+++ b/arch/arm/dts/hi3660.dtsi
@@ -1087,7 +1087,7 @@
 		};
 
 		watchdog0: watchdog@e8a06000 {
-			compatible = "arm,sp805-wdt", "arm,primecell";
+			compatible = "arm,sp805", "arm,primecell";
 			reg = <0x0 0xe8a06000 0x0 0x1000>;
 			interrupts = <GIC_SPI 44 IRQ_TYPE_LEVEL_HIGH>;
 			clocks = <&crg_ctrl HI3660_OSC32K>;
@@ -1095,7 +1095,7 @@
 		};
 
 		watchdog1: watchdog@e8a07000 {
-			compatible = "arm,sp805-wdt", "arm,primecell";
+			compatible = "arm,sp805", "arm,primecell";
 			reg = <0x0 0xe8a07000 0x0 0x1000>;
 			interrupts = <GIC_SPI 45 IRQ_TYPE_LEVEL_HIGH>;
 			clocks = <&crg_ctrl HI3660_OSC32K>;