ALSA: hda/realtek - Don't detect LO jack when identical with HP

The spec->autocfg.line_out_pins[] may contain the same pins as hp_pins[]
depending on the configuration.  When they are identical, detecting the
line_jack_present flag screws up the auto-mute because alc_line_automute()
is called unconditionally at initialization while it won't be triggered
by unsol events, thus the old line_jack_present flag is kept for the
whole run.

For fixing this buggy behavior, the driver needs to check whether the
line-outs are really individual, and skip if same as headphone jacks.

Reference: https://bugzilla.novell.com/show_bug.cgi?id=716104

Signed-off-by: Takashi Iwai <tiwai@suse.de>