ALSA: line6/toneport: Move setup_timer() at the beginning

... so that timer_del_sync() in the destructor can be called safely at
any time.  Also move the mod_timer() call in toneport_setup(), which
is a bit clearer place.

Tested-by: Chris Rorvick <chris@rorvick.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>