i82801gx: replace cafed00d/cafebabe by defines

i82801gx: replace cafed00d/cafebabe by defines

We're using '0xcafed00d' all over the code as magic for ACPI S3
resume. Let's add a define for that. Also replace 0xcafebabe by
a define.

Change-Id: I5f5dc09561679d19f98771c4f81830a50202c69f
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Reviewed-on: http://review.coreboot.org/33
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>