Correct typos in docs strings (#5233)

lib/ansible/modules/network/netvisor/pn_trunk.py

@@ -105,10 +105,10 @@ options:
   pn_mirror_receive:
     description:
       - Specify if the configuration receives mirrored traffic.
-  pn_unkown_ucast_level:
+  pn_unknown_ucast_level:
     description:
       - Specify an unkown unicast level in percent. The default value is 100%.
-  pn_unkown_mcast_level:
+  pn_unknown_mcast_level:
     description:
       - Specify an unkown multicast level in percent. The default value is 100%.
   pn_broadcast_level:

lib/ansible/modules/network/nxos/nxos_ntp_options.py

@@ -40,7 +40,7 @@ options:
         required: false
         default: null
         choices: ['true','false']
-    stratrum:
+    stratum:
         description:
             - If C(master=true), an optional stratum can be supplied (1-15).
               The device default is 8.