While at it add DECLARE_AMD_DEV() and DECLARE_NV_DEV() macros
(ala piix.h:DECLARE_PIIX_DEV() added by jgarzik).

Acked by Vojtech.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@elka.pw.edu.pl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>