powerpc/fsl_pci: Add support for FSL PCIe controllers v2.x

powerpc/fsl_pci: Add support for FSL PCIe controllers v2.x

FSL PCIe controller v2.1:
     - New MSI inbound window
     - Same Inbound windows address as PCIe controller v1.x

Added new pit_t member(pmit) to struct ccsr_pci for MSI inbound window

FSL PCIe controller v2.2 and v2.3:
     - Different addresses for PCIe inbound window 3,2,1
     - Exposed PCIe inbound window 0
     - New PCIe interrupt status register

Added new config and interrupt Status register to struct ccsr_pci & updated
pit_t array size to reflect the 4 inbound windows.

Device tree is used to maintain backward compatibility i.e. update inbound
window 1 index depending upon "compatible" field witin PCIE node.

Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Acked-by: Roy Zang <tie-fei.zang@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>