arm64: dts: sprd: fix the cpu node for UMS512

The UMS512 Socs have 8 cores contains 6 a55 and 2 a75.
modify the cpu nodes to correct information.

Fixes: 2b488183 ("arm64: dts: sprd: Add support for Unisoc's UMS512")
Cc: stable@vger.kernel.org
Signed-off-by: Cixi Geng <cixi.geng1@unisoc.com>
Link: https://lore.kernel.org/r/20230711162346.5978-1-cixi.geng@linux.devSigned-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>

arch/arm64/boot/dts/sprd/ums512.dtsi

@@ -96,7 +96,7 @@ CPU5: cpu@500 {
 
 		CPU6: cpu@600 {
 			device_type = "cpu";
-			compatible = "arm,cortex-a55";
+			compatible = "arm,cortex-a75";
 			reg = <0x0 0x600>;
 			enable-method = "psci";
 			cpu-idle-states = <&CORE_PD>;
@@ -104,7 +104,7 @@ CPU6: cpu@600 {
 
 		CPU7: cpu@700 {
 			device_type = "cpu";
-			compatible = "arm,cortex-a55";
+			compatible = "arm,cortex-a75";
 			reg = <0x0 0x700>;
 			enable-method = "psci";
 			cpu-idle-states = <&CORE_PD>;