PCI/switchtec: Add Gen4 device IDs

Now that Gen4 is properly supported, advertise support in the module's
device ID table and add the same IDs to the list of switchtec quirks.

[logang@deltatee.com: add commit message and quirk IDs]
Link: https://lore.kernel.org/r/20200115035648.2578-8-logang@deltatee.com


Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>