I am afraid to say that the Chipset P55 works with two USB controllers only based on the design of the product.
You can check this information at the following link on page 40:
in that case is any other Intel iCore (any generation) chipset that has more than 2 USB Controller? if not, how do I get around it to use devices like multiple kinects?
I am afraid to say that the configuration of multiple Kinects on the system will be provided by the system manufacturer only.
From our side, based on the design of this specific chipset, it supports up to 14 USB ports with two USB controllers.