mfd: Make TPS65910 usable without interrupts

TPS65910 can be used without interrupts.
Hence let probe succeed in case interrupt can't be
configured and let Kernel only to complain about it

Signed-off-by: Afzal Mohammed <afzal@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/tps65910-irq.c b/drivers/mfd/tps65910-irq.c
index a56be93..95c0d79 100644
--- a/drivers/mfd/tps65910-irq.c
+++ b/drivers/mfd/tps65910-irq.c
@@ -215,6 +215,7 @@
 
 int tps65910_irq_exit(struct tps65910 *tps65910)
 {
-	free_irq(tps65910->chip_irq, tps65910);
+	if (tps65910->chip_irq)
+		free_irq(tps65910->chip_irq, tps65910);
 	return 0;
 }