regmap: Add generic macro to define regmap_irq

Add REGMAP_IRQ_REG macro in regmap.h to define regmap_irq
structure easily for other driver module.

Signed-off-by: Qipeng Zha <qipeng.zha@intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

include/linux/regmap.h

@@ -791,6 +791,9 @@ struct regmap_irq {
 	unsigned int mask;
 };
 
+#define REGMAP_IRQ_REG(_irq, _off, _mask)		\
+	[_irq] = { .reg_offset = (_off), .mask = (_mask) }
+
 /**
  * Description of a generic regmap irq_chip.  This is not intended to
  * handle every possible interrupt controller, but it should handle a