MAINTAINERS: fix update references to stm32 audio bindings

MAINTAINERS: fix update references to stm32 audio bindings

The 00d38fd8d2524 ("MAINTAINERS: update references to stm32 audio bindings")
commit update the bindings reference, by
removing bindings/sound/st,stm32-adfsdm.txt, to set the
new reference to bindings/iio/adc/st,stm32-*.yaml.

This leads to "get_maintainer finds" the match for the
Documentation/devicetree/bindings/iio/adc/st,stm32-dfsdm-adc.yaml,
but also to the IIO bindings
Documentation/devicetree/bindings/iio/adc/st,stm32-adc.yaml

And The commit fixes only a part of the problem:
Documentation/devicetree/bindings/sound/st,stm32-*.txt file have been
also moved to yaml.

Update references to include all stm32 audio bindings file and
exclude the st,stm32-adc.yaml bindings file.

cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Fixes: 0d38fd8d2524 ("MAINTAINERS: update references to stm32 audio bindings")
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Link: https://lore.kernel.org/r/20210909145449.24388-1-arnaud.pouliquen@foss.st.com
Signed-off-by: Mark Brown <broonie@kernel.org>