parisc: firmware: Fix sparse context imbalance warnings

Tell sparse about correct context for pdc_cpu_rendezvous_*lock()
functions.

Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/kernel/firmware.c

@@ -334,15 +334,15 @@ int __pdc_cpu_rendezvous(void)
 /**
  * pdc_cpu_rendezvous_lock - Lock PDC while transitioning to rendezvous state
  */
-void pdc_cpu_rendezvous_lock(void)
+void pdc_cpu_rendezvous_lock(void) __acquires(&pdc_lock)
 {
 	spin_lock(&pdc_lock);
 }
 
 /**
  * pdc_cpu_rendezvous_unlock - Unlock PDC after reaching rendezvous state
  */
-void pdc_cpu_rendezvous_unlock(void)
+void pdc_cpu_rendezvous_unlock(void) __releases(&pdc_lock)
 {
 	spin_unlock(&pdc_lock);
 }