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>