powerpc/pseries: Add Initialization of VF Bars

When enabling SR-IOV in pseries platform, the VF bar properties for a
PF are reported on the device node in the device tree.

This patch adds the IOV Bar resources to Linux structures from the
device tree for later use when configuring SR-IOV by PF driver.

Signed-off-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Signed-off-by: Juan J. Alvarez <jjalvare@linux.vnet.ibm.com>
Acked-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>