mfd: Use irq_desc_get_xxx() to avoid redundant lookup of irq_desc

Use irq_desc_get_xxx() to avoid redundant lookup of irq_desc while we
already have a pointer to corresponding irq_desc.

Do the same change to avoid the pattern "irq_get_chip_data(data->irq)".

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/t7l66xb.c b/drivers/mfd/t7l66xb.c
index cc281032..16fc1ad 100644
--- a/drivers/mfd/t7l66xb.c
+++ b/drivers/mfd/t7l66xb.c
@@ -187,7 +187,7 @@
 /* Handle the T7L66XB interrupt mux */
 static void t7l66xb_irq(unsigned int irq, struct irq_desc *desc)
 {
-	struct t7l66xb *t7l66xb = irq_get_handler_data(irq);
+	struct t7l66xb *t7l66xb = irq_desc_get_handler_data(desc);
 	unsigned int isr;
 	unsigned int i, irq_base;