MAINTAINERS: Update Wolfson Micro section to include CS47L24 source

The CS47L24 source is part of the ex-Wolfson "Arizona" group of
drivers. Not all cs47lxx devices are part of the Arizona driver
group so the cs47l24 is explicitly listed by its full part number.

Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>