powerpc/pseries: Fix PCI config address for DDW

[ Upstream commit 8a934efe94347eee843aeea65bdec8077a79e259 ]

In commit 8445a87f7092 "powerpc/iommu: Remove the dependency on EEH
struct in DDW mechanism", the PE address was replaced with the PCI
config address in order to remove dependency on EEH. According to PAPR
spec, firmware (pHyp or QEMU) should accept "xxBBSSxx" format PCI config
address, not "xxxxBBSS" provided by the patch. Note that "BB" is PCI bus
number and "SS" is the combination of slot and function number.

This fixes the PCI address passed to DDW RTAS calls.

Fixes: 8445a87f7092 ("powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism")
Cc: stable@vger.kernel.org # v3.4+
Reported-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Tested-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>