Update tests for compatibility with recent changes

Commit 038a51cdc8 introduced a change
where the sshd_config file is not managed unless the 'sshd_config'
pillar variable is defined. The kitchen tests did not define that
variable, so they stopped working.

This change sets a default value for 'Port' so the file is managed
by Salt.

.kitchen.yml

         '*':
           - openssh
     openssh.sls:
+      sshd_config:
+        Port: 22
+      ssh_config:
+        Port: 22
       openssh:
         sshd_config_mode: '600'