arm64: dts: msm8998: thermal: Restrict thermal zone name length to under 20

The thermal core restricts names of thermal zones to under 20
characters. Fix the names for a couple of msm8998 thermal zones.
Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Marc Gonzalez <marc.w.gonzalez@free.fr>
Signed-off-by: Andy Gross <agross@kernel.org>

arch/arm64/boot/dts/qcom/msm8998.dtsi

@@ -536,7 +536,7 @@ gpu2_alert0: trip-point@0 {
 			};
 		};
 
-		cluster0-mhm-thermal {
+		clust0-mhm-thermal {
 			polling-delay-passive = <250>;
 			polling-delay = <1000>;
 
@@ -551,7 +551,7 @@ cluster0_mhm_alert0: trip-point@0 {
 			};
 		};
 
-		cluster1-mhm-thermal {
+		clust1-mhm-thermal {
 			polling-delay-passive = <250>;
 			polling-delay = <1000>;