zdev: Add support for handling auto-configuration data

Auto-configuration is the name of a new configuration target that is
supported by chzdev and lszdev besides the existing active and
persistent configuration targets. Directives created in this new
configuration are stored as udev rules in the /run/udev/rules.d
directory.

Auto-configuration directives are only in effect if there are no
directives for the same device in the user-provided persistent
configuration. This allows users to override auto-configuration
directives if necessary.

Due to the volatile nature of the /run directory, auto-configuration
directives are cleared on reboot. Therefore mechanisms that generate
auto-configuration directives must recreate them on every boot.

The lszdev tool displays auto-configuration data both in list view
as well as in detail view. Users can specify the new option --auto-conf
to only show data from this configuration target.

Mechanisms that generate automated configuration directives can use
chzdev together with the --auto-conf option to create the corresponding
udev rules.

Note: This change does not include a mechanism that generates
      auto-configuration directives.

Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

zdev/src/lszdev_usage.txt

@@ -41,5 +41,6 @@ OPTIONS
   -n, --no-headings      Do not print column headings
       --base PATH        Use PATH as base for accessing files
       --pairs            Produce output in KEY="VALUE" format
+      --auto-conf        Only show auto-configuration data
   -V, --verbose          Print additional run-time information
   -q, --quiet            Print only minimal run-time information