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>

irqchip: vf610-mscm: Add Vybrid MSCM bindings

Add binding documentation for CPU configuration and interrupt router
submodule of the Miscellaneous System Control Module. The MSCM is
used in all variants of Freescale Vybrid SoC's.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Link: https://lkml.kernel.org/r/1425249689-32354-3-git-send-email-stefan@agner.ch
Signed-off-by: Jason Cooper <jason@lakedaemon.net>