spi: sh-hspi: Make of_device_id array const

Make of_device_id array const, because all OF functions handle
it as const.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/spi/spi-sh-hspi.c

@@ -304,7 +304,7 @@ static int hspi_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static struct of_device_id hspi_of_match[] = {
+static const struct of_device_id hspi_of_match[] = {
 	{ .compatible = "renesas,hspi", },
 	{ /* sentinel */ }
 };