netdev-genl: spec: Add PID in netdev netlink YAML spec

Add support in netlink spec(netdev.yaml) for PID of the
NAPI thread. Add code generated from the spec.

Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com>
Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Link: https://lore.kernel.org/r/170147335301.5260.11872351477120434501.stgit@anambiarhost.jf.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/netlink/specs/netdev.yaml

@@ -230,6 +230,12 @@ attribute-sets:
         name: irq
         doc: The associated interrupt vector number for the napi
         type: u32
+      -
+        name: pid
+        doc: PID of the napi thread, if NAPI is configured to operate in
+             threaded mode. If NAPI is not in threaded mode (i.e. uses normal
+             softirq context), the attribute will be absent.
+        type: u32
   -
     name: queue
     attributes:
@@ -389,6 +395,7 @@ operations:
             - id
             - ifindex
             - irq
+            - pid
       dump:
         request:
           attributes: