PM QOS update

This patch changes the string based list management to a handle base
implementation to help with the hot path use of pm-qos, it also renames
much of the API to use "request" as opposed to "requirement" that was
used in the initial implementation.  I did this because request more
accurately represents what it actually does.

Also, I added a string based ABI for users wanting to use a string
interface.  So if the user writes 0xDDDDDDDD formatted hex it will be
accepted by the interface.  (someone asked me for it and I don't think
it hurts anything.)

This patch updates some documentation input I got from Randy.

Signed-off-by: markgross <mgross@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 8728876..605c86d 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -481,11 +481,13 @@
 	snd_pcm_timer_resolution_change(substream);
 	runtime->status->state = SNDRV_PCM_STATE_SETUP;
 
-	pm_qos_remove_requirement(PM_QOS_CPU_DMA_LATENCY,
-				substream->latency_id);
+	if (substream->latency_pm_qos_req) {
+		pm_qos_remove_request(substream->latency_pm_qos_req);
+		substream->latency_pm_qos_req = NULL;
+	}
 	if ((usecs = period_to_usecs(runtime)) >= 0)
-		pm_qos_add_requirement(PM_QOS_CPU_DMA_LATENCY,
-					substream->latency_id, usecs);
+		substream->latency_pm_qos_req = pm_qos_add_request(
+					PM_QOS_CPU_DMA_LATENCY, usecs);
 	return 0;
  _error:
 	/* hardware might be unuseable from this time,
@@ -540,8 +542,8 @@
 	if (substream->ops->hw_free)
 		result = substream->ops->hw_free(substream);
 	runtime->status->state = SNDRV_PCM_STATE_OPEN;
-	pm_qos_remove_requirement(PM_QOS_CPU_DMA_LATENCY,
-		substream->latency_id);
+	pm_qos_remove_request(substream->latency_pm_qos_req);
+	substream->latency_pm_qos_req = NULL;
 	return result;
 }