CPP is ran with src/ as part of its search path, so
using <northbridge/...> and the like is safe.
Change-Id: I644d60190ac92ef284d5f0b4acf44f7db3c788ee
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/649
Tested-by: build bot (Jenkins)