MAINTAINERS: Update Cirrus Logic Codecs maintainers

Add patches@opensource.cirrus.com to the main group of Cirrus
Logic ASoC codec drivers.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20200925105908.20640-3-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: rfvirgil

MAINTAINERS

@@ -4154,6 +4154,7 @@ CIRRUS LOGIC AUDIO CODEC DRIVERS
 M:	James Schulman <james.schulman@cirrus.com>
 M:	David Rhodes <david.rhodes@cirrus.com>
 L:	alsa-devel@alsa-project.org (moderated for non-subscribers)
+L:	patches@opensource.cirrus.com
 S:	Maintained
 F:	sound/soc/codecs/cs*