netlink: specs: devlink: replace underscores with dashes in names

We're trying to add a strict regexp for the name format in the spec.
Underscores will not be allowed, dashes should be used instead.
This makes no difference to C (codegen, if used, replaces special
chars in names) but it gives more uniform naming in Python.

Fixes: 429ac62114 ("devlink: define enum for attr types of dynamic attributes")
Fixes: f2f9dd164d ("netlink: specs: devlink: add the remaining command to generate complete split_ops")
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20250624211002.3475021-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/netlink/specs/devlink.yaml

@@ -38,15 +38,15 @@ definitions:
       -
         name: dsa
       -
-        name: pci_pf
+        name: pci-pf
       -
-        name: pci_vf
+        name: pci-vf
       -
         name: virtual
       -
         name: unused
       -
-        name: pci_sf
+        name: pci-sf
   -
     type: enum
     name: port-fn-state
@@ -220,7 +220,7 @@ definitions:
       -
         name: flag
       -
-        name: nul_string
+        name: nul-string
         value: 10
       -
         name: binary