mfd: Allow platforms to specify an IRQ base for WM8350

This is currently unused by the wm8350 drivers but getting it merged
now will reduce merge issues in the future when implementing wm8350
genirq support.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

include/linux/mfd/wm8350/core.h

@@ -646,10 +646,12 @@ struct wm8350 {
  * @init: Function called during driver initialisation.  Should be
  *        used by the platform to configure GPIO functions and similar.
  * @irq_high: Set if WM8350 IRQ is active high.
+ * @irq_base: Base IRQ for genirq (not currently used).
  */
 struct wm8350_platform_data {
 	int (*init)(struct wm8350 *wm8350);
 	int irq_high;
+	int irq_base;
 };