The following corrects how we pass CPU flags to gas.  Previous, AFLAGS
was incorrectly assumed to be pased directly to $(AS), which is not the
case.

Concept ack'd by Sam Ravnborg.
Signed-off-by: Tom Rini <trini@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>