pm: device: adjust flag names

Some flags were using `FLAGS` instead of `FLAG`.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
diff --git a/include/pm/device.h b/include/pm/device.h
index 9227be8..244c615 100644
--- a/include/pm/device.h
+++ b/include/pm/device.h
@@ -53,9 +53,9 @@
 	 * Indicates whether or not the device is capable of waking the system
 	 * up.
 	 */
-	PM_DEVICE_FLAGS_WS_CAPABLE,
+	PM_DEVICE_FLAG_WS_CAPABLE,
 	/** Indicates if the device is being used as wakeup source. */
-	PM_DEVICE_FLAGS_WS_ENABLED,
+	PM_DEVICE_FLAG_WS_ENABLED,
 };
 
 /** @brief Device PM actions. */
@@ -137,7 +137,7 @@
 		.flags = ATOMIC_INIT(COND_CODE_1(			\
 				DT_NODE_EXISTS(node_id),		\
 				(DT_PROP_OR(node_id, wakeup_source, 0)),\
-				(0)) << PM_DEVICE_FLAGS_WS_CAPABLE),	\
+				(0)) << PM_DEVICE_FLAG_WS_CAPABLE),	\
 	}
 
 /**
diff --git a/subsys/pm/device.c b/subsys/pm/device.c
index 3346a58..1dfc066 100644
--- a/subsys/pm/device.c
+++ b/subsys/pm/device.c
@@ -153,15 +153,15 @@
 
 	flags =	atomic_get(&pm->flags);
 
-	if ((flags & BIT(PM_DEVICE_FLAGS_WS_CAPABLE)) == 0U) {
+	if ((flags & BIT(PM_DEVICE_FLAG_WS_CAPABLE)) == 0U) {
 		return false;
 	}
 
 	if (enable) {
 		new_flags = flags |
-			BIT(PM_DEVICE_FLAGS_WS_ENABLED);
+			BIT(PM_DEVICE_FLAG_WS_ENABLED);
 	} else {
-		new_flags = flags & ~BIT(PM_DEVICE_FLAGS_WS_ENABLED);
+		new_flags = flags & ~BIT(PM_DEVICE_FLAG_WS_ENABLED);
 	}
 
 	return atomic_cas(&pm->flags, flags, new_flags);
@@ -176,7 +176,7 @@
 	}
 
 	return atomic_test_bit(&pm->flags,
-			       PM_DEVICE_FLAGS_WS_ENABLED);
+			       PM_DEVICE_FLAG_WS_ENABLED);
 }
 
 bool pm_device_wakeup_is_capable(const struct device *dev)
@@ -188,5 +188,5 @@
 	}
 
 	return atomic_test_bit(&pm->flags,
-			       PM_DEVICE_FLAGS_WS_CAPABLE);
+			       PM_DEVICE_FLAG_WS_CAPABLE);
 }