verilog-mode.el: Don't bind `inhibit-point-motion-hooks`

verilog-mode.el: Don't bind `inhibit-point-motion-hooks`

Keep binding it in Emacs<25 but not in Emacs≥25 (where such bindings
are redundant and the var is declared obsolete).

* lisp/progmodes/verilog-mode.el (verilog-save-buffer-state):
Don't bind `inhibit-point-motion-hooks` if Emacs≥25.
(verilog-save-font-no-change-functions): Same, and refrain from
binding `before/after-change-functions` as well while we're at it,
since `inhibit-modification-hooks` already covers it in Emacs≥25.