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-davinci.c b/drivers/spi/spi-davinci.c
index 50b13c9..b141ef2 100644
--- a/drivers/spi/spi-davinci.c
+++ b/drivers/spi/spi-davinci.c
@@ -299,16 +299,15 @@
 	 * Assign function pointer to appropriate transfer method
 	 * 8bit, 16bit or 32bit transfer
 	 */
-	if (bits_per_word <= 8 && bits_per_word >= 2) {
+	if (bits_per_word <= 8) {
 		dspi->get_rx = davinci_spi_rx_buf_u8;
 		dspi->get_tx = davinci_spi_tx_buf_u8;
 		dspi->bytes_per_word[spi->chip_select] = 1;
-	} else if (bits_per_word <= 16 && bits_per_word >= 2) {
+	} else {
 		dspi->get_rx = davinci_spi_rx_buf_u16;
 		dspi->get_tx = davinci_spi_tx_buf_u16;
 		dspi->bytes_per_word[spi->chip_select] = 2;
-	} else
-		return -EINVAL;
+	}
 
 	if (!hz)
 		hz = spi->max_speed_hz;
@@ -933,6 +932,7 @@
 	master->dev.of_node = pdev->dev.of_node;
 	master->bus_num = pdev->id;
 	master->num_chipselect = pdata->num_chipselect;
+	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 16);
 	master->setup = davinci_spi_setup;
 
 	dspi->bitbang.chipselect = davinci_spi_chipselect;