PCI: switchtec: Add support for PCIe Gen5 devices

[ Upstream commit 0fb53e64

 ]

Advertise support of Gen5 devices in the driver's device ID table and
add the same IDs for the switchtec quirks. Also update driver code to
accommodate them.

Link: https://lore.kernel.org/r/20230624000003.2315364-3-kelvin.cao@microchip.com
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>