Add missed arm,num-irq-priority-bits to fix below CHECK_DTBS warning:
arm/boot/dts/nxp/lpc/lpc4337-ciaa.dtb: interrupt-controller@e000e100 (arm,armv7m-nvic): 'arm,num-irq-priority-bits' is a required property
from schema $id: http://devicetree.org/schemas/interrupt-controller/arm,nvic.yaml#
Signed-off-by: Frank Li <Frank.Li@nxp.com> Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>