Documentation: Fix pci=config_acs= example

JIRA: https://issues.redhat.com/browse/RHEL-83611
Upstream Status: b388face5f169e7a41c1b5e1cdd20515160a83b3

commit b388face5f169e7a41c1b5e1cdd20515160a83b3
Author: Akihiko Odaki <akihiko.odaki@daynix.com>
Date:   Sun Sep 15 10:36:58 2024 +0900

    Documentation: Fix pci=config_acs= example

    The documentation currently says:

      config_acs=
                      Format:
                      <ACS flags>@<pci_dev>[; ...]
                      Specify one or more PCI devices (in the format
                      specified above) optionally prepended with flags
                      and separated by semicolons. The respective
                      capabilities will be enabled, disabled or
                      unchanged based on what is specified in
                      flags.
               (...)
                      For example,
                        pci=config_acs=10x
                      would configure all devices that support
                      ACS to enable P2P Request Redirect, disable
                      Translation Blocking, and leave Source
                      Validation unchanged from whatever power-up
                      or firmware set it to.

    See the complete documentation at:

      https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html

    However, a flag specification always needs to be suffixed with "@" and
    a PCI valid device address, which is missing in this example. Also, to
    configure all devices that support ACS, the flag needs to be suffixed
    with "@pci:0:0", for the ACS support to be enabled.

    Fix the documentation so the example is correct.

    Link: https://lore.kernel.org/r/20240915-acs-v1-1-b9ee536ee9bd@daynix.com


Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
    [kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Signed-off-by: Myron Stowe <mstowe@redhat.com>