ARM: dts: nspire: Fix arm primecell compatible string

Commit c44e0503 ("docs: dt: fix documented Primecell compatible string")
removed the last occurrence of incorrect "arm,amba-primecell" compatible
string, but somehow one occurrence of the same is left in the nspire platform.

Fix the same by replacing it with the correct "arm,primecell" compatible.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20230711092617.1412815-1-sudeep.holla@arm.comSigned-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/boot/dts/nspire/nspire.dtsi

@@ -161,7 +161,7 @@ timer1: timer@900d0000 {
 			};
 
 			watchdog: watchdog@90060000 {
-				compatible = "arm,amba-primecell";
+				compatible = "arm,primecell";
 				reg = <0x90060000 0x1000>;
 				interrupts = <3>;
 			};