ASoC: max98090/91: added DAPM widget for digital output for max98091

ASoC: max98090/91: added DAPM widget for digital output for max98091

Added DAPM widget for digital output path from codec to the
CPU DAI (capture) for secondary digital mic. "AIFOUT2L" is the
left audio channel output and "AIFOUT2R" is the right audio
channel output, both belonging to the stream "HiFi Capture".
Stream index given as 2 and 3 respectively, as 0 and 1 belongs
to "AIFOUTL" and "AIFOUTR" of the primary digital mic. Now
with this commit the total channels increase to 4, so changing
the ".channels_max" for ".capture" to 4 accordingly in the
"struct snd_soc_dai_driver max98090_dai". This will work
for max98090 and max98091 both because in case of max98090
only 1 or 2 channels could be used and in case of max98091
maximum 4 channels could be used. Both the cases get satisfied with
".channels_max" as 4.

Signed-off-by: Sharique Mohammad <sharq0406@gmail.com>
Link: https://patch.msgid.link/20251021145611.1750689-1-sharq0406@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>