Add few missing prototypes, and remove few unused (thus lonelly) variables.

Add few missing prototypes, and remove few unused (thus lonelly) variables.
TODO
 - x86emu need (imo) some common header with prototypes at least
 - clog2, ulzma, hardwaremain prototypes added by this patch probably should
   be moved to some header too.
 - in src/devices/device_util.c prototype is before function because seems,
   it is used only within same file, if not it should be moved to debug
   section of prototypes in include/device/device.h

Signed-off-by: Maciej Pijanka <maciej.pijanka@gmail.com>
Acked-by: Myles Watson <mylesgw@gmail.com>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@4871 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1