Docs: dt: add #msi-cells to GICv3 ITS binding
Docs: dt: add #msi-cells to GICv3 ITS binding

The GICv3 ITS uses sideband master identification data (known as a
DeviceID) to identify which master wrote to a doorbell, and this data is
used to determine how to react in response to the write.

Commit 1e6db000482fa65a ("irqchip/gicv3-its: Add platform MSI support")
added support per this binding, but failed to update the documentation.
This patch fixes the documentation.

Signed-off-by: Mark Rutland <1db9dd262beaa64f35756dd39531d9747b7778bb@arm.com>
Acked-by: Marc Zyngier <a16cc0c82647c52d401177f8e50567df5499e36c@arm.com>
Cc: Rob Herring <988782c95b9025801edfc9a5b1fd5a8e93699e07@kernel.org>
Signed-off-by: Rob Herring <fbb37eacae100e13076d5c4b46f06cfa4d6fa9f8@kernel.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs