drm/xe/vf: Don't expose sysfs attributes not applicable for VFs

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: drm/xe/vf: Don't expose sysfs attributes not applicable for VFs VFs can't read BMG_PCIE_CAP(0x138340) register nor access PCODE (already guarded by the info.skip_pcode flag) so we shouldn't expose attributes that require any of them to avoid errors like: [] xe 0000:03:00.1: [drm] Tile0: GT0: VF is trying to read an \ inaccessible register 0x138340+0x0 [] RIP: 0010:xe_gt_sriov_vf_read32+0x6c2/0x9a0 [xe] [] Call Trace: [] xe_mmio_read32+0x110/0x280 [xe] [] auto_link_downgrade_capable_show+0x2e/0x70 [xe] [] dev_attr_show+0x1a/0x70 [] sysfs_kf_seq_show+0xaa/0x120 [] kernfs_seq_show+0x41/0x60 (cherry picked from commit a2d6223d224f333f705ed8495bf8bebfbc585c35)

References

• https://git.kernel.org/stable/c/bacbadedbba737da8ae6e0464bc0971c30cda4cb
• https://git.kernel.org/stable/c/500dad428e5b0de4c1bdfa893822a6e06ddad0b5