dt-bindings: pinctrl: sirf: Fix typo abitrary

Fix comment typo.
s/abitrary/arbitrary/
Signed-off-by: Naoki Hayama <naoki.hayama@lineo.co.jp>
Link: https://lore.kernel.org/r/614fe604-ab8e-21cb-0c3a-db6ddeff2a4e@lineo.co.jpSigned-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/pinctrl/pinctrl-atlas7.txt

@@ -60,7 +60,7 @@ For example, pinctrl might have properties like the following:
 Please refer to pinctrl-bindings.txt in this directory for details of the common
 pinctrl bindings used by client devices.
 
-SiRFatlas7's pinmux nodes act as a container for an abitrary number of subnodes.
+SiRFatlas7's pinmux nodes act as a container for an arbitrary number of subnodes.
 Each of these subnodes represents some desired configuration for a group of pins.
 
 Required subnode-properties: