Stub out FILE*, stdout/stdin/stderr and implement fprintf on these

Stub out FILE*, stdout/stdin/stderr and implement fprintf on these

- Add FILE*
- Add stdout, stdin, stderr stubs
- Add fprintf that redirects to printf for stdout and stderr and fails otherwise

Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com>
Acked-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@6358 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1