dt-bindings: arm: fix typos in compatible

Fix typo "cortex"

Signed-off-by: Ken Kurematsu <[e-mail]>
Acked-by: Krzysztof Kozlowski <[e-mail]>
Signed-off-by: Rob Herring <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

Documentation/devicetree/bindings/arm/bcm/brcm,bcm63138.txt

···
 
 	cpus {
 		cpu@0 {
-			compatible = "arm,cotex-a9";
+			compatible = "arm,cortex-a9";
 			reg = <0>;
 			...
 			enable-method = "brcm,bcm63138";