arm: dts: k3-j721e-r5-common-proc-board: tps659413: Correct the min/max voltages of VDD_CPU

Correct the min/max voltages of VDD_CPU. As per data sheet the VDD_CPU
minimum voltage is .6V & maximum voltage is .9V.

Correct the same. While at it fix the comment to reflect VDD_CPU
instead of VDD_MPU.

Data Sheet Link: https://www.ti.com/lit/gpn/dra829v

Signed-off-by: Keerthy <j-keerthy@ti.com>
diff --git a/arch/arm/dts/k3-j721e-r5-common-proc-board.dts b/arch/arm/dts/k3-j721e-r5-common-proc-board.dts
index 54f8353..a14b148 100644
--- a/arch/arm/dts/k3-j721e-r5-common-proc-board.dts
+++ b/arch/arm/dts/k3-j721e-r5-common-proc-board.dts
@@ -259,10 +259,10 @@
 		regulators: regulators {
 			u-boot,dm-spl;
 			buck12_reg: buck12 {
-				/*VDD_MPU*/
+				/*VDD_CPU*/
 				regulator-name = "buck12";
-				regulator-min-microvolt = <800000>;
-				regulator-max-microvolt = <1250000>;
+				regulator-min-microvolt = <600000>;
+				regulator-max-microvolt = <900000>;
 				regulator-always-on;
 				regulator-boot-on;
 				u-boot,dm-spl;