Rearrange some Tramp declarations

Rearrange some Tramp declarations

* lisp/net/tramp.el (tramp-prefix-format, tramp-prefix-regexp)
(tramp-method-regexp, tramp-postfix-method-format)
(tramp-postfix-method-regexp, tramp-prefix-ipv6-format)
(tramp-prefix-ipv6-regexp, tramp-postfix-ipv6-format)
(tramp-postfix-ipv6-regexp, tramp-postfix-host-format)
(tramp-postfix-host-regexp, tramp-remote-file-name-spec-regexp)
(tramp-file-name-structure, tramp-file-name-regexp)
(tramp-completion-method-regexp)
(tramp-completion-file-name-regexp):
* lisp/net/tramp-gvfs.el (tramp-gvfs-dbus-event-vector):
Rearrange declarations.