ALSA: hda/realtek - Cannot adjust speaker's volume on Dell XPS 27 7760

The issue is the same as commit dd9aa335 ("ALSA: hda/realtek - Can't
adjust speaker's volume on a Dell AIO"), the output requires to connect
to a node with Amp-out capability.

Applying the same fixup ALC298_FIXUP_SPK_VOLUME can fix the issue.

BugLink: https://bugs.launchpad.net/bugs/1775068


Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>