PCI: dwc: Fix dw_pcie_ep_raise_msix_irq() to get correct MSI-X table address

commit beb4641a ("PCI: dwc: Add MSI-X callbacks handler"),
in order to raise MSI-X interrupt, obtained MSIX table address from
Base Address Register (BAR). However BAR only holds PCI address
programmed by the host whereas the MSI-X table should be in the local
memory.

Store the MSI-X table address (virtual address) as part of ->set_bar()
callback and use that to get the message address and message data
here.

Fixes: beb4641a ("PCI: dwc: Add MSI-X callbacks handler")
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>