powerpc/52xx: Use DEFINE_SPINLOCK

SPIN_LOCK_UNLOCKED is deprecated.  The following makes the change suggested
in Documentation/spinlocks.txt

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
declarer name DEFINE_SPINLOCK;
identifier xxx_lock;
@@

- spinlock_t xxx_lock = SPIN_LOCK_UNLOCKED;
+ DEFINE_SPINLOCK(xxx_lock);
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/52xx/mpc52xx_common.c

@@ -42,7 +42,7 @@ static struct of_device_id mpc52xx_bus_ids[] __initdata = {
  * from interrupt context while node mapping (which calls ioremap())
  * cannot be used at such point.
  */
-static spinlock_t mpc52xx_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(mpc52xx_lock);
 static struct mpc52xx_gpt __iomem *mpc52xx_wdt;
 static struct mpc52xx_cdm __iomem *mpc52xx_cdm;