Convert the NXP LPC18xx Watchdog Timer bindings to yaml format.

Cc: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Animesh Agarwal <animeshagarwal28@gmail.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240814061210.56213-1-animeshagarwal28@gmail.comSigned-off-by: Rob Herring (Arm) <robh@kernel.org>