hw/xen: set pci Atomic Ops requests for passthrough device

hw/xen: set pci Atomic Ops requests for passthrough device

Make guest os access pci device control 2 reg for passthrough device
as struct XenPTRegInfo described in the file hw/xen/xen_pt.h.
/* reg read only field mask (ON:RO/ROS, OFF:other) */
uint32_t ro_mask;
/* reg emulate field mask (ON:emu, OFF:passthrough) */
uint32_t emu_mask;

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1196
Signed-off-by: Aaron Liu <Aaron.Liu@amd.com>
Signed-off-by: Ruili Ji <ruili.ji@amd.com>
Message-ID: <BL1PR12MB599341DC55BA53FE588DE14E9B7E9@BL1PR12MB5993.namprd12.prod.outlook.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>