commit 3856081e upstream.

The current POST code for the AST2300/2400 family doesn't work properly
if the chip hasn't been initialized previously by either the BMC own FW
or the VBIOS. This fixes it.
Signed-off-by: Y.C. Chen <yc_chen@aspeedtech.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Y.C. Chen <yc_chen@aspeedtech.com>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>