dt-bindings: remove 'interrupt-parent' from bindings

'interrupt-parent' is often documented as part of define bindings, but
it is really outside the scope of a device binding. It's never required
in a given node as it is often inherited from a parent node. Or it can
be implicit if a parent node is an 'interrupt-controller' node. So
remove it from all the binding files.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/interrupt-controller/marvell,odmi-controller.txt

@@ -26,8 +26,6 @@ Required properties:
                          See Documentation/devicetree/bindings/interrupt-controller/arm,gic.txt
                          for details about the GIC Device Tree binding.
 
-- interrupt-parent     : Reference to the parent interrupt controller.
-
 Example:
 
 	odmi: odmi@300000 {