PCI/switchtec: Add support for Intercomm Notify and Upstream Error Containment

Add support for the Inter Fabric Manager Communication (Intercomm) Notify
event in PAX variants of Switchtec hardware and the Upstream Error
Containment port in the MR1 release of Gen3 firmware.

Link: https://lore.kernel.org/r/20200106190337.2428-4-logang@deltatee.com


Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>