ALSA: hda/realtek: Enable 4-speaker output Dell Precision 5570 laptop

The Dell Precision 5570 uses the same 4-speakers-on-ALC289 just like the
previous Precision 5560. I replicated that patch onto this one, and can
confirm that the audio is much better (the woofers are now working);
I've tested it on my Dell Precision 5570.

Signed-off-by: Callum Osmotherly <callum.osmotherly@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/YyGbWM5wEoFMbW2v@piranha
Signed-off-by: Takashi Iwai <tiwai@suse.de>