Fix spelling of "transferred".

Signed-off-by: Vagrant Cascadian <vagrant@debian.org>
Acked-by: Marek Vasut <marex@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/doc/device-tree-bindings/spi/spi-bus.txt b/doc/device-tree-bindings/spi/spi-bus.txt
index 5c8720a..420ec95 100644
--- a/doc/device-tree-bindings/spi/spi-bus.txt
+++ b/doc/device-tree-bindings/spi/spi-bus.txt
@@ -63,7 +63,7 @@
 		      a header byte before reading data from the slave.
 
 Some SPI controllers and devices support Dual and Quad SPI transfer mode.
-It allows data in SPI system transfered in 2 wires(DUAL) or 4 wires(QUAD).
+It allows data in SPI system transferred in 2 wires(DUAL) or 4 wires(QUAD).
 Now the value that spi-tx-bus-width and spi-rx-bus-width can receive is
 only 1(SINGLE), 2(DUAL) and 4(QUAD).
 Dual/Quad mode is not allowed when 3-wire mode is used.