Added type definitions for signal types that are used multiple times

Created by: christian-herber-nxp

This is a little request for comments. I felt it would make sense to introduce some type definitions to reduce the amount of duplication in the specification. Especially for more complex definitions like the registerflags, this allows good reuse without having to define it over and over. Seemed a better solution to me over the previously defined derived parameter. This adds hyperlinks where the types are used that take you to the type definition.