ALSA: hda/realtek: fix the hp playback volume issue for LG machines

Recently we tested the headphone playback on 2 LG machines, if we set
the volume to the max value or near to the max value, the sound is too
loud, it could even bring harm to listeners.

A workaround is to decrease the max volume to a reasonable value for
the headphone's amplifier, then the users couldn't set the volume
bigger than that value from the userspace.

Signed-off-by: Hui Wang <hui.wang@canonical.com>
Message-ID: <20240318011128.156023-1-hui.wang@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>