spi: sh-msiof: Remove casts to drop constness

Now the chip select APIs take const pointers, there is no longer a need
to cast away constness.

Fixes: 9e264f3f ("spi: Replace all spi->chip_select and spi->cs_gpiod references with function call")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/bc14c7c75f8d63c5c11f61f80daaa53b12bb15fb.1678704562.git.geert+renesas@glider.beSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-sh-msiof.c

@@ -587,11 +587,11 @@ static int sh_msiof_prepare_message(struct spi_controller *ctlr,
 	u32 ss, cs_high;
 
 	/* Configure pins before asserting CS */
-	if (spi_get_csgpiod((struct spi_device *)spi, 0)) {
+	if (spi_get_csgpiod(spi, 0)) {
 		ss = ctlr->unused_native_cs;
 		cs_high = p->native_cs_high;
 	} else {
-		ss = spi_get_chipselect((struct spi_device *)spi, 0);
+		ss = spi_get_chipselect(spi, 0);
 		cs_high = !!(spi->mode & SPI_CS_HIGH);
 	}
 	sh_msiof_spi_set_pin_regs(p, ss, !!(spi->mode & SPI_CPOL),