drivers: bluetooth: hci: nrf53: use nrf_spu_extdomain_set

Instead of hardcoded values and device instances.

Signed-off-by: Gerard Marull-Paretas <gerard@teslabs.com>

drivers/bluetooth/hci/nrf53_support.c

@@ -6,9 +6,12 @@
 
 #include <soc.h>
 #include <zephyr/device.h>
+#include <zephyr/devicetree.h>
 #include <nrf53_cpunet_mgmt.h>
 #include <../subsys/bluetooth/controller/ll_sw/nordic/hal/nrf5/debug.h>
 
+#include <hal/nrf_spu.h>
+
 #define LOG_LEVEL CONFIG_BT_HCI_DRIVER_LOG_LEVEL
 #include <zephyr/logging/log.h>
 LOG_MODULE_REGISTER(bt_hci_nrf53_support);
@@ -34,7 +37,7 @@ int bt_hci_transport_setup(const struct device *dev)
 	/* Retain nRF5340 Network MCU in Secure domain (bus
 	 * accesses by Network MCU will have Secure attribute set).
 	 */
-	NRF_SPU->EXTDOMAIN[0].PERM = 1 << 4;
+	nrf_spu_extdomain_set((NRF_SPU_Type *)DT_REG_ADDR(DT_NODELABEL(spu)), 0, true, false);
 #endif /* !defined(CONFIG_TRUSTED_EXECUTION_NONSECURE) */
 
 	/* Release the Network MCU, 'Release force off signal' */