hwspinlock/core: simplify 'owner' handling

Use struct device_driver's owner member instead of asking drivers to
explicitly pass the owner again.

This simplifies drivers and also save some memory, since there's no
point now in maintaining a separate owner pointer per hwspinlock.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
diff --git a/Documentation/hwspinlock.txt b/Documentation/hwspinlock.txt
index 7dcd1a4..bbaa464 100644
--- a/Documentation/hwspinlock.txt
+++ b/Documentation/hwspinlock.txt
@@ -256,18 +256,16 @@
  * @ops: vendor-specific hwspinlock handlers
  * @id: a global, unique, system-wide, index of the lock.
  * @lock: initialized and used by hwspinlock core
- * @owner: underlying implementation module, used to maintain module ref count
  */
 struct hwspinlock {
 	struct device *dev;
 	const struct hwspinlock_ops *ops;
 	int id;
 	spinlock_t lock;
-	struct module *owner;
 };
 
-The underlying implementation is responsible to assign the dev, ops, id and
-owner members. The lock member, OTOH, is initialized and used by the hwspinlock
+The underlying implementation is responsible to assign the dev, ops and id
+members. The lock member, OTOH, is initialized and used by the hwspinlock
 core.
 
 6. Implementation callbacks