netlink: specs: wrap long doc lines (>80 chars)

Clean up all line too long errors reported by yamllint in the netlink
specs, e.g.

    error    line too long (97 > 80 characters)  (line-length)

Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> # mptcp_pm.yaml
Link: https://patch.msgid.link/20250610125944.85265-7-donald.hunter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/netlink/specs/ethtool.yaml

@@ -55,7 +55,9 @@ definitions:
         doc: The firmware flashing process was stopped due to an error.
   -
     name: c33-pse-ext-state
-    doc: "groups of PSE extended states functions. IEEE 802.3-2022 33.2.4.4 Variables"
+    doc: |
+      "groups of PSE extended states functions. IEEE 802.3-2022 33.2.4.4
+      Variables"
     type: enum
     name-prefix: ethtool-c33-pse-ext-state-
     header: linux/ethtool.h