dt-bindings: interrupt-controller: fsl,mu-msi: Drop "interrupt-controller" property

The Freescale MU-MSI is an MSI provider, not an interrupt provider, so
drop the "interrupt-controller" property. This fixes dtc "interrupt_provider"
warning.

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240925173438.1906339-1-robh@kernel.org


Signed-off-by: Rob Herring (Arm) <robh@kernel.org>