spi: spi-uclass: Set slave wordlen with SPI_DEFAULT_WORDLEN

In some case wordlen may not be set. Use SPI_DEFAULT_WORDLEN as default.

Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jagan Teki <jteki@openedev.com>

drivers/spi/spi-uclass.c

@@ -158,6 +158,7 @@ static int spi_child_pre_probe(struct udevice *dev)
 	slave->max_hz = plat->max_hz;
 	slave->mode = plat->mode;
 	slave->mode_rx = plat->mode_rx;
+	slave->wordlen = SPI_DEFAULT_WORDLEN;
 
 	return 0;
 }