ALSA: hda/realtek - Fix Headphone Mic doesn't recording for ALC256

Switch default pcbeep path to Line in path.

Signed-off-by: Kailang Yang <kailang@realtek.com>
Tested-by: Hui Wang <hui.wang@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>