#2 Support for repeating structures

[Silvan Wegmann]

Some register maps contain regular structures of repeating registers that are currently not satisfyingly supported by the XSD.
A single repeated register can provisionally be implemented in the form of a register range. However there is no support for an automatic index in names or the description.
Multiple repeating registers (ex. a UART baud rate register and a UART config register for several UARTs) are not supported at all and have to be written out.