ARM: pxa: magician: use platform driver for audio

The magician audio driver creates a codec device and gets
data from a board specific header file, both of which is
a bit suspicious. Move these into the board file itself,
using a gpio lookup table.

Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: alsa-devel@alsa-project.org
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>