vfio/igd: add macro for declaring mirrored registers

vfio/igd: add macro for declaring mirrored registers

igd devices have multipe registers mirroring mmio address and pci
config space, more than a single BDSM register. To support this,
the read/write functions are made common and a macro is defined to
simplify the declaration of MemoryRegionOps.

Signed-off-by: Tomita Moeko <tomitamoeko@gmail.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Link: https://lore.kernel.org/r/20241206122749.9893-8-tomitamoeko@gmail.com
[ clg : Fixed conversion specifier on 32-bit platform ]
Signed-off-by: Cédric Le Goater <clg@redhat.com>