PM / QoS: Prepare struct dev_pm_qos_request for more request types

The subsequent patches will use struct dev_pm_qos_request for
representing both latency requests and flags requests.  To make that
easier, put the node member of struct dev_pm_qos_request (under the
name "pnode") into a union called "data" that will represent the
request's  value and list node depending on its type.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: mark gross <markgross@thegnar.org>
diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index b91dc6f..54c61ff 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -221,7 +221,7 @@
 static ssize_t pm_qos_latency_show(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%d\n", dev->power.pq_req->node.prio);
+	return sprintf(buf, "%d\n", dev->power.pq_req->data.pnode.prio);
 }
 
 static ssize_t pm_qos_latency_store(struct device *dev,