mfd: Convert WM8350 to use request_threaded_irq()

Instead of hand rolling our own variant.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

include/linux/mfd/wm8350/core.h

@@ -626,7 +626,6 @@ struct wm8350 {
 	struct mutex auxadc_mutex;
 
 	/* Interrupt handling */
-	struct work_struct irq_work;
 	struct mutex irq_mutex; /* IRQ table mutex */
 	struct wm8350_irq irq[WM8350_NUM_IRQ];
 	int chip_irq;