Revert "ALSA: hda - Add mute-LED mode control to Thinkpad"

This reverts commit 7290006d.

Through the regression report, it was revealed that the
tpacpi_led_set() call to thinkpad_acpi helper doesn't only toggle the
mute LED but actually mutes the sound.  This is contradiction to the
expectation, and rather confuses user.

According to Henrique, it's not trivial to judge which TP model
behaves "LED-only" and which model does whatever more intrusive, as
Lenovo's implementations vary model by model.  So, from the safety
reason, we should revert the patch for now.

Reported-by: Martin Steigerwald <martin@lichtvoll.de>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>