mfd: da9052: Constify spi_device_id

spi_device_id are not supposed to change at runtime. All functions
working with spi_device_id provided by <linux/i2c.h> work with
const spi_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/da9052-spi.c

@@ -67,7 +67,7 @@ static int da9052_spi_remove(struct spi_device *spi)
 	return 0;
 }
 
-static struct spi_device_id da9052_spi_id[] = {
+static const struct spi_device_id da9052_spi_id[] = {
 	{"da9052", DA9052},
 	{"da9053-aa", DA9053_AA},
 	{"da9053-ba", DA9053_BA},