docs: netdevsim: fixe typo in netdevsim documentation

Fixed a typographical error in "Rate objects" section

Reviewed-by: Joe Damato <[e-mail]>
Reviewed-by: Breno Leitao <[e-mail]>
Signed-off-by: Dave Marquardt <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

Documentation/networking/devlink/netdevsim.rst

···
 
 The ``netdevsim`` driver supports rate objects management, which includes:
 
-- registerging/unregistering leaf rate objects per VF devlink port;
+- registering/unregistering leaf rate objects per VF devlink port;
 - creation/deletion node rate objects;
 - setting tx_share and tx_max rate values for any rate object type;
 - setting parent node for any rate object type.