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-sirf.c b/drivers/spi/spi-sirf.c
index 0808cd5..77497be 100644
--- a/drivers/spi/spi-sirf.c
+++ b/drivers/spi/spi-sirf.c
@@ -425,10 +425,6 @@
 		rxfifo_ctrl = SIRFSOC_SPI_FIFO_THD(SIRFSOC_SPI_FIFO_SIZE / 2) |
 					SIRFSOC_SPI_FIFO_WIDTH_DWORD;
 		break;
-	default:
-		dev_err(&spi->dev, "Bits per word %d not supported\n",
-		       bits_per_word);
-		return -EINVAL;
 	}
 
 	if (!(spi->mode & SPI_CS_HIGH))
@@ -556,6 +552,8 @@
 	sspi->bitbang.txrx_bufs = spi_sirfsoc_transfer;
 	sspi->bitbang.master->setup = spi_sirfsoc_setup;
 	master->bus_num = pdev->id;
+	master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(12) |
+					SPI_BPW_MASK(16) | SPI_BPW_MASK(32);
 	sspi->bitbang.master->dev.of_node = pdev->dev.of_node;
 
 	sspi->p = pinctrl_get_select_default(&pdev->dev);