ARM: OMAP: omap_device: remove omap_device_parent

Currently all omap_devices are forced to have the dummy device
'omap_device_parent' as a parent.  This was used to distinguish
omap_devices from "normal" platform_devices in the OMAP PM core code.

Now that we implement the PM core using PM domains, this is no longer
needed, and is removed.

This also frees up omap_devices to have a more complex parent/child
relationships that model actual device relationships.

The only in-tree user of omap_device_parent was the OMAP PM layer to
handle lost-context count for omap_devices.  That is now converted to
use the presence of the omap_device_pm_domain instead.

Signed-off-by: Kevin Hilman <khilman@ti.com>
diff --git a/arch/arm/plat-omap/omap-pm-noop.c b/arch/arm/plat-omap/omap-pm-noop.c
index 3dc3801..5a97b4d 100644
--- a/arch/arm/plat-omap/omap-pm-noop.c
+++ b/arch/arm/plat-omap/omap-pm-noop.c
@@ -319,7 +319,7 @@
 	if (WARN_ON(!dev))
 		return -ENODEV;
 
-	if (dev->parent == &omap_device_parent) {
+	if (dev->pm_domain == &omap_device_pm_domain) {
 		count = omap_device_get_context_loss_count(pdev);
 	} else {
 		WARN_ONCE(off_mode_enabled, "omap_pm: using dummy context loss counter; device %s should be converted to omap_device",