dt-bindings: iommu: Drop client node in examples

There's no need to show consumer side in provider examples. The ones
used here are undocumented or undocumented in schemas which results in
warnings.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220422192104.2591462-1-robh@kernel.org


Signed-off-by: Joerg Roedel <jroedel@suse.de>