dt-bindings: opp: opp-v2-kryo-cpu: Document named opp-microvolt property

Document named opp-microvolt property for opp-v2-kryo-cpu schema.
This property is used to declare multiple voltage ranges selected on the
different values read from efuses. The selection is done based on the
speed pvs values and the named opp-microvolt property is selected by the
qcom-cpufreq-nvmem driver.

Signed-off-by: Christian Marangi <[e-mail]>
Reviewed-by: Rob Herring <[e-mail]>
Signed-off-by: Viresh Kumar <[e-mail]>

Documentation/devicetree/bindings/opp/opp-v2-kryo-cpu.yaml

···
           6:  MSM8996SG, speedbin 2
           7-31:  unused
 
+          Bitmap for IPQ806x SoC:
+          0:  IPQ8062
+          1:  IPQ8064/IPQ8066/IPQ8068
+          2:  IPQ8065/IPQ8069
+          3-31:  unused
+
           Other platforms use bits directly corresponding to speedbin index.
 
       clock-latency-ns: true
···
                 opp-supported-hw = <0x1>;
                 clock-latency-ns = <200000>;
                 required-opps = <&cpr_opp6>;
+            };
+        };
+
+        /* Dummy opp table to give example for named opp-microvolt */
+        opp-table-2 {
+            compatible = "operating-points-v2-krait-cpu";
+            nvmem-cells = <&speedbin_efuse>;
+
+            opp-384000000 {
+                opp-hz = /bits/ 64 <384000000>;
+                opp-microvolt-speed0-pvs0 = <1000000 950000 1050000>;
+                opp-microvolt-speed0-pvs1 = <925000 878750 971250>;
+                opp-microvolt-speed0-pvs2 = <875000 831250 918750>;
+                opp-microvolt-speed0-pvs3 = <800000 760000 840000>;
+                opp-supported-hw = <0x7>;
+                clock-latency-ns = <100000>;
             };
         };