ALSA: ctxfi: Add support for dedicated RCA switching

ALSA: ctxfi: Add support for dedicated RCA switching

Add feature to support switching between the dedicated RCA output and
the 7.1ch Front output. This is required for hardware that utilizes
separate DAC circuits for RCA and 7.1ch channels.

Changes:
 - Add dedicated_rca capability flag
 - Add "Analog Playback Route" mixer control
 - Implement logic to swap DAO inputs between RCA and Front ports

Signed-off-by: Harin Lee <me@harin.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20251124180501.2760421-6-me@harin.net