dt-bindings: interrupt-controller: realtek,rtl-intc: Add rtl9300-intc

Add a compatible string for the interrupt controller found on the
rtl930x SoCs. The interrupt controller has registers for VPE1 so these
are added as a second reg cell.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>