PCI: Add #defines for accessing PCIe DVSEC fields

mainline inclusion
from mainline-v5.17-rc1
commit 80b3485f
category: bugfix
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I8C8B4
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=80b3485f7d7bdb2468f2a9d6a346a1132d248309



-------------------------------------

Intel-SIG: commit 80b3485f PCI: Add #defines for accessing PCIe DVSEC fields
Backport SPR and EMR IOMMU PCIe related upstream bugfixes to kernel 5.10.

Add #defines for accessing Vendor ID, Revision, Length, and ID offsets
in the Designated Vendor Specific Extended Capability (DVSEC). Defined
in PCIe r5.0, sec 7.9.6.

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Link: https://lore.kernel.org/r/20211208015015.891275-2-david.e.box@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 80b3485f)
Signed-off-by: Ethan Zhao <haifeng.zhao@linux.intel.com>