ALSA: hda/realtek: enable headset mic on Latitude 5420 Rugged

Like many Dell laptops, the 3.5mm port by default can not detect a
combined headphones+mic headset or even a pure microphone.  This
change enables the port's functionality.

Signed-off-by: Jonathan Lane <jon@borg.moe>
Cc: <stable@vger.kernel.org>
Link: https://patch.msgid.link/20250611193124.26141-2-jon@borg.moe


Signed-off-by: Takashi Iwai <tiwai@suse.de>