nrf what?: Enable cpusec_cpuapp_ipc and bellboard

Not sure about the correct tag here. Should we enable
this upstream or keep it as noup for now?

Signed-off-by: Georgios Vasilakis <[email protected]>

Author: Vge0rge

boards/nordic/nrf54h20dk/nrf54h20dk_nrf54h20_cpuapp.dts

@@ -152,11 +152,16 @@
 };
 
 &cpusec_cpuapp_ipc {
+	status = "okay";
 	mbox-names = "tx", "rx";
 	tx-region = <&cpuapp_cpusec_ipc_shm>;
 	rx-region = <&cpusec_cpuapp_ipc_shm>;
 };
 
+&cpusec_bellboard {
+	status = "okay";
+};
+
 ipc0: &cpuapp_cpurad_ipc {
 	status = "okay";
 	mbox-names = "rx", "tx";