[TODO] firmware: arm_scmi: Enable SCMI mailbox layer use MHUv2

[HACK]firmware: arm_scmi: Make MHUv1 MHUv2 coexist
[TC2] Simplify MHUv2 channels registration
[TC2] use shmem/mboxes to choose MHUv1/2 channels

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
Using DT

                        compatible = "arm,scmi-shmem";
                        reg = <0x0 0x80>;
                };
+
+               scp_cpu_scmi_mem: scp-shmem@80 {
+                       compatible = "arm,scmi-shmem";
+                       reg = <0x80 0x80>;
+               };
        };

        mbox_db_rx: mhu@45010000 {
@@ -270,8 +275,8 @@
        scmi {
                compatible = "arm,scmi";
                mbox-names = "tx", "rx";
-               mboxes = <&mbox_db_tx 0 0 &mbox_db_rx 0 0 >;
-               shmem = <&cpu_scp_scmi_mem &cpu_scp_scmi_mem>;
+               mboxes = <&mbox_db_tx 0 0 &mbox_db_rx 0 0 &mbox_db_rx 0 1>;
+               shmem = <&cpu_scp_scmi_mem &scp_cpu_scmi_mem>;
                #address-cells = <1>;
                #size-cells = <0>;

@@ -284,6 +289,11 @@
                        reg = <0x14>;
                        #clock-cells = <1>;
                };
+
+               scmi_sensors0: protocol@15 {
+                       reg = <0x15>;
+                       #thermal-sensor-cells = <1>;
+               };
        };