spi: st-ssc4: Remove duplicate code to test unsupported mode bits

spi_setup() will test unsupported mode bits before calling spi->master->setup.
Thus remove duplicate code to test unsupported mode bits in spi_st_setup().
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-st-ssc4.c

@@ -217,12 +217,6 @@ static int spi_st_setup(struct spi_device *spi)
 	int cs = spi->cs_gpio;
 	int ret;
 
-	if (spi->mode & ~MODEBITS) {
-		dev_err(&spi->dev, "unsupported mode bits 0x%x\n",
-			spi->mode & ~MODEBITS);
-		return -EINVAL;
-	}
-
 	if (!hz)  {
 		dev_err(&spi->dev, "max_speed_hz unspecified\n");
 		return -EINVAL;