mfd: Constify regmap and irq configuration data

Constify in various drivers configuration data which is not modified:
 - regmap_irq_chip,
 - individual regmap_irq's in array,
 - regmap_config,
 - irq_domain_ops,

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/da9150-core.c b/drivers/mfd/da9150-core.c
index 5549817..94b9bbd 100644
--- a/drivers/mfd/da9150-core.c
+++ b/drivers/mfd/da9150-core.c
@@ -164,7 +164,7 @@
 }
 EXPORT_SYMBOL_GPL(da9150_bulk_write);
 
-static struct regmap_irq da9150_irqs[] = {
+static const struct regmap_irq da9150_irqs[] = {
 	[DA9150_IRQ_VBUS] = {
 		.reg_offset = 0,
 		.mask = DA9150_E_VBUS_MASK,
@@ -251,7 +251,7 @@
 	},
 };
 
-static struct regmap_irq_chip da9150_regmap_irq_chip = {
+static const struct regmap_irq_chip da9150_regmap_irq_chip = {
 	.name = "da9150_irq",
 	.status_base = DA9150_EVENT_E,
 	.mask_base = DA9150_IRQ_MASK_E,