spi: sc18is602: Convert to use bits_per_word_mask

Since commit 543bb25 "spi: add ability to validate xfer->bits_per_word in SPI
core", the driver can set bits_per_word_mask for the master then the SPI core
will reject transfers that attempt to use an unsupported bits_per_word value.
So we can remove the bits_per_word checking in sc18is602_check_transfer() and
let SPI core handle the checking.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/spi/spi-sc18is602.c

@@ -183,18 +183,11 @@ static int sc18is602_setup_transfer(struct sc18is602 *hw, u32 hz, u8 mode)
 static int sc18is602_check_transfer(struct spi_device *spi,
 				    struct spi_transfer *t, int tlen)
 {
-	int bpw;
 	uint32_t hz;
 
 	if (t && t->len + tlen > SC18IS602_BUFSIZ)
 		return -EINVAL;
 
-	bpw = spi->bits_per_word;
-	if (t && t->bits_per_word)
-		bpw = t->bits_per_word;
-	if (bpw != 8)
-		return -EINVAL;
-
 	hz = spi->max_speed_hz;
 	if (t && t->speed_hz)
 		hz = t->speed_hz;
@@ -315,6 +308,7 @@ static int sc18is602_probe(struct i2c_client *client,
 	}
 	master->bus_num = client->adapter->nr;
 	master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LSB_FIRST;
+	master->bits_per_word_mask = SPI_BPW_MASK(8);
 	master->setup = sc18is602_setup;
 	master->transfer_one_message = sc18is602_transfer_one;
 	master->dev.of_node = np;