[SPARC64]: Privatize sun5_timer.

It is only used by some localized code in irq.c, and also
delete enable_prom_timer() as that is totally unused.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc64/kernel/irq.c b/arch/sparc64/kernel/irq.c
index daa2fb9..c9b6916 100644
--- a/arch/sparc64/kernel/irq.c
+++ b/arch/sparc64/kernel/irq.c
@@ -782,8 +782,14 @@
 }
 #endif
 
+struct sun5_timer {
+	u64	count0;
+	u64	limit0;
+	u64	count1;
+	u64	limit1;
+};
 
-struct sun5_timer *prom_timers;
+static struct sun5_timer *prom_timers;
 static u64 prom_limit0, prom_limit1;
 
 static void map_prom_timers(void)
@@ -839,18 +845,6 @@
 	: "g1", "g2");
 }
 
-void enable_prom_timer(void)
-{
-	if (!prom_timers)
-		return;
-
-	/* Set it to whatever was there before. */
-	prom_timers->limit1 = prom_limit1;
-	prom_timers->count1 = 0;
-	prom_timers->limit0 = prom_limit0;
-	prom_timers->count0 = 0;
-}
-
 void init_irqwork_curcpu(void)
 {
 	register struct irq_work_struct *workp asm("o2");