doc: uniphier: reformat reStructuredText manually
doc: uniphier: reformat reStructuredText manually

Commit 6f6257476754 ("Convert documentation to reStructuredText")
automatically converted all documents by a tool.  I see some parts
were converted in an ugly way (or, at least, it is not my intention).
Also, the footnote is apparently broken.

I checked this document by my eyes, and reformated it so that it looks
nicer both in plain text and reST form.

Signed-off-by: Masahiro Yamada <378b411a8a63ecc7605ec4272234862d7781c6ae@socionext.com>

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware