[POWERPC] Fix cell pmu initialisation

Make sure that the pmu is not initialised unless we are running on a cell.
Also make the init routine static.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

arch/powerpc/platforms/cell/pmu.c

@@ -382,11 +382,14 @@ static irqreturn_t cbe_pm_irq(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-int __init cbe_init_pm_irq(void)
+static int __init cbe_init_pm_irq(void)
 {
 	unsigned int irq;
 	int rc, node;
 
+	if (!machine_is(cell))
+		return 0;
+
 	for_each_node(node) {
 		irq = irq_create_mapping(NULL, IIC_IRQ_IOEX_PMI |
 					       (node << IIC_IRQ_NODE_SHIFT));