serial: 8250: Convert timers to use timer_setup()

serial: 8250: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Jiri Slaby <jslaby@suse.com>
Cc: Vignesh R <vigneshr@ti.com>
Cc: Ed Blake <ed.blake@imgtec.com>
Cc: Matthias Brugger <mbrugger@suse.com>
Cc: Sean Young <sean@mess.org>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>