spi: convert drivers to use bits_per_word_mask

Fill in the recently added spi_master.bits_per_word_mask field in as
many drivers as possible. Make related cleanups, such as removing any
redundant error-checking, or empty setup callbacks.

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c
index 24610ca..0ef05f1 100644
--- a/drivers/spi/spi-fsl-espi.c
+++ b/drivers/spi/spi-fsl-espi.c
@@ -144,10 +144,6 @@
 	if (!bits_per_word)
 		bits_per_word = spi->bits_per_word;
 
-	/* Make sure its a bit width we support [4..16] */
-	if ((bits_per_word < 4) || (bits_per_word > 16))
-		return -EINVAL;
-
 	if (!hz)
 		hz = spi->max_speed_hz;
 
@@ -157,12 +153,10 @@
 	cs->get_tx = mpc8xxx_spi_tx_buf_u32;
 	if (bits_per_word <= 8) {
 		cs->rx_shift = 8 - bits_per_word;
-	} else if (bits_per_word <= 16) {
+	} else
 		cs->rx_shift = 16 - bits_per_word;
 		if (spi->mode & SPI_LSB_FIRST)
 			cs->get_tx = fsl_espi_tx_buf_lsb;
-	} else {
-		return -EINVAL;
 	}
 
 	mpc8xxx_spi->rx_shift = cs->rx_shift;
@@ -609,6 +603,7 @@
 	if (ret)
 		goto err_probe;
 
+	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
 	master->setup = fsl_espi_setup;
 
 	mpc8xxx_spi = spi_master_get_devdata(master);