mfd: intel_soc_pmic: Constify ACPI device ids

Constify the ACPI device ID array, it doesn't need to be writable at
runtime.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/intel_soc_pmic_core.c b/drivers/mfd/intel_soc_pmic_core.c
index 7b50b6b..27e7552 100644
--- a/drivers/mfd/intel_soc_pmic_core.c
+++ b/drivers/mfd/intel_soc_pmic_core.c
@@ -147,7 +147,7 @@
 MODULE_DEVICE_TABLE(i2c, intel_soc_pmic_i2c_id);
 
 #if defined(CONFIG_ACPI)
-static struct acpi_device_id intel_soc_pmic_acpi_match[] = {
+static const struct acpi_device_id intel_soc_pmic_acpi_match[] = {
 	{"INT33FD", (kernel_ulong_t)&intel_soc_pmic_config_crc},
 	{ },
 };