MIPS: RB532: Cleanup the headers again

This patch cleans up headers and regroups informations to
where they should reside. While moving, try to have a
consistant naming for defines.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>