ASoC: bring cs4270 feature/limitations list in sync

Removes numbers from the list of features/limitations and makes it
reflect recent changes to the code.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Acked-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>