imx233: extend partition window support to be more generic

The new code can select among several types of window (user, system, ...).
Furthermore, the type of partitions to use is selectable in config file.
Currently, two types are support: Freescale style MBR and Creative MBLK

Change-Id: I969d60a3d08f2c9448fb4b9c440051b7801b94cd
8 files changed