PCI: dwc: Fix MSI-X EP framework address calculation bug
Fix an error caused by 3-bit right rotation on offset address
calculation of MSI-X table in dw_pcie_ep_raise_msix_irq().
The initial testing code was setting by default the offset address of
MSI-X table to zero, so that even with a 3-bit right rotation the
computed result would still be zero and valid, therefore this bug went
unnoticed.