[nrf fromlist] soc: nordic: nrf54h: gpd: fix compile warning when CONFIG_DEBUG=y

Usage of K_SPINLOCK with CONFIG_DEBUG=y seems to trigger a compiler
warning about request not always being initialized. Fallback to
k_spin_lock/unlock calls to fix this issue.

Upstream PR #: 80908

Signed-off-by: Gerard Marull-Paretas <[email protected]>
(cherry picked from commit 2dbc7cf1fe16f01bd83d495d9ee5fd18e0b8f2f3)

Author: gmarull

soc/nordic/nrf54h/gpd/gpd.c

@@ -93,16 +93,19 @@ static int nrf_gpd_sync(struct gpd_onoff_manager *gpd_mgr)
 {
 	int64_t start;
 	nrfs_err_t err;
+	k_spinlock_key_t key;
 	gdpwr_request_type_t request;
 
-	K_SPINLOCK(&gpd_mgr->mgr.lock) {
-		if (gpd_mgr->mgr.refs == 0) {
-			request = GDPWR_POWER_REQUEST_CLEAR;
-		} else {
-			request = GDPWR_POWER_REQUEST_SET;
-		}
+	key = k_spin_lock(&gpd_mgr->mgr.lock);
+
+	if (gpd_mgr->mgr.refs == 0) {
+		request = GDPWR_POWER_REQUEST_CLEAR;
+	} else {
+		request = GDPWR_POWER_REQUEST_SET;
 	}
 
+	k_spin_unlock(&gpd_mgr->mgr.lock, key);
+
 	atomic_clear_bit(&gpd_service_status, GPD_SERVICE_REQ_ERR);
 	atomic_clear_bit(&gpd_service_status, GPD_SERVICE_REQ_OK);