i965: Reorganize MESA_FORMAT -> BRW_SURFACEFORMAT table.

i965: Reorganize MESA_FORMAT -> BRW_SURFACEFORMAT table.

This should be a no-op change.  The initializers are reordered to
match the ordering of the enum, since there isn't a clearly sensible
ordering, but "the order they were added to the driver, sort of" is
definitely not one.

Also, the unsupported formats are explicitly initialized to 0, so it's
more obvious what we aren't claiming to support.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>