sparc: PCI: Fix incorrect address calculation of PCI Bridge windows on Simba-bridges

The SIMBA APB Bridges lacks the 'ranges' of-property describing the
PCI I/O and memory areas located beneath the bridge. Faking this
information has been performed by reading range registers in the
APB bridge, and calculating the corresponding areas.

In commit 01f94c4a
("Fix sabre pci controllers with new probing scheme.") a bug was
introduced into this calculation, causing the PCI memory areas
to be calculated incorrectly: The shift size was set to be
identical for I/O and MEM ranges, which is incorrect.

This patch set the shift size of the MEM range back to the
value used before 01f94c4a

.

Signed-off-by: Kjetil Oftedal <oftedal@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>