ALSA: line6: Fix POD X3 Live audio input

The commit c039aaa7 was incomplete,
missing part of the setup for Live. This makes also audio input work,
in addition to audio output.

Fixes: c039aaa7
Reported-by: Eddi De Pieri <eddi@depieri.net>
Signed-off-by: Andrej Krutak <dev@andree.sk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>