drivers: spi: fix some typos

Fix some typos in spi drivers

Signed-off-by: Pengfei Fan <fanpengfei1@eswincomputing.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/drivers/spi/omap3_spi.c b/drivers/spi/omap3_spi.c
index ea38a0f..1cbb5d4 100644
--- a/drivers/spi/omap3_spi.c
+++ b/drivers/spi/omap3_spi.c
@@ -142,7 +142,7 @@
 			}
 		}
 
-		/* Disable the channel to prevent furher receiving */
+		/* Disable the channel to prevent further receiving */
 		if (i == (len - 1))
 			omap3_spi_set_enable(priv, OMAP3_MCSPI_CHCTRL_DIS);