ALSA: hda - switch lfe with side in mixer for 4930g

Built-in sub-woofer can now be controlled by lfe slider instead of
side slider on Acer Aspire 5930g

Signed-off-by: Łukasz Wojniłowicz <lukasz.wojnilowicz@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>