PCI: tegra: Support MSI 64-bit addressing

The MSI target address can reside beyond the 32-bit boundary on devices
with more than 2 GiB of system memory.  The PCI host bridge on Tegra can
easily support 64-bit addresses, so make sure to pass the upper 32 bits of
the target address to endpoints when allocating MSI entries.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Stephen Warren <swarren@nvidia.com>