vfio: selftests: Support DMR and GNR-D DSA devices

vfio: selftests: Support DMR and GNR-D DSA devices

Currently, the VFIO DSA driver test only supports the SPR DSA device ID.
Attempting to run the test on newer platforms like DMR or GNR-D results
in a "No driver found" error, causing the test to be skipped.

Refactor dsa_probe() to use a switch statement for checking device IDs.
This improves maintainability and makes it easier to add new device IDs
in the future.

Add the following DSA device IDs to the supported list:
PCI_DEVICE_ID_INTEL_DSA_DMR  (0x1212)
PCI_DEVICE_ID_INTEL_DSA_GNRD (0x11fb)

Signed-off-by: Yi Lai <yi1.lai@intel.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20260320010930.481380-1-yi1.lai@intel.com
Signed-off-by: Alex Williamson <alex@shazbot.org>