staging: skein: move macros into header file

Move macro definitions from source file into respective header file

This concludes macro cleanup as outlined in TODO
Signed-off-by: Dmytro Shynkevych <dm.shynk@gmail.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>