video-rice: Remove duplicate params for VIWidth and VIHeight.

Not sure why we needed another setting for this when it was already
provided by the upstream implementation. If anyone knows, please let me
know.
video-rice: Removed unneeded screen xpos, ypos fields.

These values are computed on the fly and do not need to be persisted
or retrieved from the config file.

Config.cpp and Config.h are now identical to upstream.
video-rice: More reversions related to previous two commits.

Reverts some changes made in commits
27d588752d984e8ffc17e2598f70ffddb3ab21b4
16c83a535b854b2d2267a94a37db456108068f16