spi: sh-msiof: Constify platform_device_id

The platform_device_id is not modified by the driver and core uses it as
const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c
index bcc7c63..d3370a6 100644
--- a/drivers/spi/spi-sh-msiof.c
+++ b/drivers/spi/spi-sh-msiof.c
@@ -1263,7 +1263,7 @@
 	return 0;
 }
 
-static struct platform_device_id spi_driver_ids[] = {
+static const struct platform_device_id spi_driver_ids[] = {
 	{ "spi_sh_msiof",	(kernel_ulong_t)&sh_data },
 	{ "spi_r8a7790_msiof",	(kernel_ulong_t)&r8a779x_data },
 	{ "spi_r8a7791_msiof",	(kernel_ulong_t)&r8a779x_data },