Staging: ipack/bridges/tpci200: Put the TPCI200 control registers into a struct.

This saves us from a little pointer arithmetic and cleans up the code a bit.

Signed-off-by: Jens Taprogge <jens.taprogge@taprogge.org>
Signed-off-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>