Various Doxygen comment fixes, typo fixes, etc.

Various Doxygen comment fixes, typo fixes, etc.

 - Fix incorrect argument names for @param entries.

 - Add missing @param and @return entries, partly as TODOs.

 - s/@returns/@return/, that's a typo.

 - Small whitespace fixes while I'm at it.

 - Drop useless @brief commands, they just clutter the comments and make them
   harder to read. Doxygen has an option to always use the first sentence
   of a Doxygen-comment as @brief automatically (should be on per default).

Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de>
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5955 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1