[knife-cloud] Common short options in ssh & winrm (SSH override winrm config)

@muktaa 
I've added changes to set ssh config -x,-p,-P,-i  short options by overriding winrm short options -x(winrm-user) -p(winrm-port) -P(winrm-password) and -i(kerberos_keytab_file) respectively. 
1) This block of code should be called ONLY when protocol is ssh. Please add this check.
2) Define a private method called ssh_override_winrm and put the code in it