ALSA: jack: lineout support to jack abstraction layer

This patch introduces support for reporting SW_LINEOUT_INSERT detection events
via the jack abstraction layer.

Also adds a SND_JACK_LINEOUT define to the input system header.

Signed-off-by: Matthew Ranostay <mranostay@embeddedalley.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>