[SPARC64]: Kill cpudata->idle_volume.

Set, but never used.

We used to use this for dynamic IRQ retargetting, but that
code died a long time ago.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/asm-sparc64/cpudata.h b/include/asm-sparc64/cpudata.h
index 84656f1..c66a81b 100644
--- a/include/asm-sparc64/cpudata.h
+++ b/include/asm-sparc64/cpudata.h
@@ -19,7 +19,7 @@
 	unsigned int	__softirq_pending; /* must be 1st, see rtrap.S */
 	unsigned int	multiplier;
 	unsigned int	counter;
-	unsigned int	idle_volume;
+	unsigned int	__pad1;
 	unsigned long	clock_tick;	/* %tick's per second */
 	unsigned long	udelay_val;