We use 'priv' for private data but often use 'platdata' for platform data.
We can't really use 'pdata' since that is ambiguous (it could mean private
or platform data).
Rename some of the latter variables to end with 'plat' for consistency.
Signed-off-by: Simon Glass <sjg@chromium.org>
Convert plain text documentation to reStructuredText format and add
it to Sphinx TOC tree. No essential content change.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>