PCI: Add defines for Designated Vendor-Specific Extended Capability

mainline inclusion
from mainline-v5.11-rc1
commit 1dc2da5c
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I596K9


CVE: NA

Intel-SIG: commit 1dc2da5c PCI: Add defines for Designated Vendor-Specific
Extended Capability.
Backport for intel PMT (Platform Monitoring Technology) support
--------------------------------

Add PCIe Designated Vendor-Specific Extended Capability (DVSEC) and defines
for the header offsets. Defined in PCIe r5.0, sec 7.9.6.

Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: yingbao jia <yingbao.jia@intel.com>
Signed-off-by: Jun Tian <jun.j.tian@intel.com>